5-HT2C receptor: Difference between revisions

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{{DISPLAYTITLE:5-HT<sub>2C</sub> receptor}}
{{Infobox_gene}}


{{Wrongtitle|title=5-HT<sub>2C</sub> receptor}}
The '''5-HT<sub>2C</sub> receptor''' is a subtype of [[5-HT receptor]] that binds the [[endogenous]] [[neurotransmitter]] [[serotonin]] (5-hydroxytryptamine, 5-HT). It is a [[G protein-coupled receptor]] (GPCR) that is coupled to [[Gq alpha subunit|G<sub>q</sub>/G<sub>11</sub>]] and mediates [[EPSP|excitatory]] [[neurotransmission]]. ''HTR2C'' denotes the [[human]] [[gene]] encoding for the [[Receptor (biochemistry)|receptor]],<ref name="entrez">{{cite web | title = Entrez Gene: HTR2C 5-hydroxytryptamine (serotonin) receptor 2C | url = https://www.ncbi.nlm.nih.gov/gene/3358?ordinalpos=2&itool=EntrezSystem2.PEntrez.Gene.Gene_ResultsPanel.Gene_RVDocSum}}</ref><ref name="pmid7895773">{{cite journal | vauthors = Stam NJ, Vanderheyden P, van Alebeek C, Klomp J, de Boer T, van Delft AM, Olijve W | title = Genomic organisation and functional expression of the gene encoding the human serotonin 5-HT2C receptor | journal = European Journal of Pharmacology | volume = 269 | issue = 3 | pages = 339–48 | date = November 1994 | pmid = 7895773 | doi = 10.1016/0922-4106(94)90042-6 }}</ref> that in humans is located at the X chromosome. As males have one copy of the gene and in females one of the two copies of the gene is repressed, polymorphisms at this receptor can affect the two sexes to differing extent.
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== Structure ==
| update_page = yes
At the cell surface the receptor exists as a [[GPCR oligomer|homodimer]].<ref name="pmid22593582">{{cite journal | vauthors = Herrick-Davis K, Grinde E, Lindsley T, Cowan A, Mazurkiewicz JE | title = Oligomer size of the serotonin 5-hydroxytryptamine 2C (5-HT2C) receptor revealed by fluorescence correlation spectroscopy with photon counting histogram analysis: evidence for homodimers without monomers or tetramers | journal = The Journal of Biological Chemistry | volume = 287 | issue = 28 | pages = 23604–14 | date = July 2012 | pmid = 22593582 | pmc = 3390635 | doi = 10.1074/jbc.M112.350249 }}</ref> The crystal structure is known since 2018.<ref name="pmid29398112">{{cite journal |vauthors=Peng Y, McCorvy JD, Harpsøe K, Lansu K, Yuan S, Popov P, Qu L, Pu M, Che T, Nikolajsen LF, Huang XP, Wu Y, Shen L, Bjørn-Yoshimoto WE, Ding K, Wacker D, Han GW, Cheng J, Katritch V, Jensen AA, Hanson MA, Zhao S, Gloriam DE, Roth BL, Stevens RC, Liu ZJ |title=5-HT2C Receptor Structures Reveal the Structural Basis of GPCR Polypharmacology |journal=Cell |volume=172 |issue=4 |pages=719–730.e14 |date=February 2018 |pmid=29398112 |doi=10.1016/j.cell.2018.01.001 |url=}}</ref>
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== Distribution ==
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5-HT<sub>2C</sub> receptors are located mainly in the [[choroid plexus]],<ref>{{cite journal | vauthors = Abramowski D, Rigo M, Duc D, Hoyer D, Staufenbiel M | title = Localization of the 5-Hydroxytryptamine2c Receptor Protein in Human and Rat Brain Using Specific Antisera | journal = Neuropharmacology | volume = 34| issue = 12 | pages = 1635–1645 | date = 1995 | pmid = 8788961 | doi=10.1016/0028-3908(95)00138-7}}</ref> and in rats is also found in many other brain regions in high concentrations, including parts of the [[hippocampus]], [[anterior olfactory nucleus]], [[substantia nigra]], several [[brainstem]] nuclei, [[amygdala]], [[subthalamic nucleus]] and [[Habenula#Lateral habenula|lateral habenula]]. 5-HT<sub>2C</sub> receptors are also found on epithelial cells lining the [[Ventricular system|ventricles]].<ref>{{cite journal | vauthors = Hoffman BJ, Mezey E | title = Distribution of serotonin 5-HT1C receptor mRNA in adult rat brain | journal = FEBS Letters | volume = 247 | issue = 2 | pages = 453–62 | date = 1989 | pmid = 2714444 | doi=10.1016/0014-5793(89)81390-0}}</ref>
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== Function ==
{{GNF_Protein_box
 
| image =
The 5-HT<sub>2C</sub> receptor is one of the many binding sites for [[serotonin]]. Activation of this receptor by serotonin inhibits [[dopamine]] and [[norepinephrine]] release in certain areas of the brain.<ref name="pmid15668911">{{cite journal | vauthors = Alex KD, Yavanian GJ, McFarlane HG, Pluto CP, Pehek EA | title = Modulation of dopamine release by striatal 5-HT2C receptors | journal = Synapse | volume = 55 | issue = 4 | pages = 242–51 | date = March 2005 | pmid = 15668911 | doi = 10.1002/syn.20109 }}</ref>
| image_source =
 
| PDB =  
5-HT<sub>2C</sub> receptors are claimed to significantly regulate mood, anxiety, feeding, and reproductive behavior.<ref name="pmid17451451">{{cite journal | vauthors = Heisler LK, Zhou L, Bajwa P, Hsu J, Tecott LH | title = Serotonin 5-HT(2C) receptors regulate anxiety-like behavior | journal = Genes, Brain, and Behavior | volume = 6 | issue = 5 | pages = 491–6 | date = July 2007 | pmid = 17451451 | doi = 10.1111/j.1601-183X.2007.00316.x }}</ref> 5-HT<sub>2C</sub> receptors regulate dopamine release in the [[striatum]], [[prefrontal cortex]], [[nucleus accumbens]], [[hippocampus]], [[hypothalamus]], and [[amygdala]], among others.
| Name = 5-hydroxytryptamine (serotonin) receptor 2C
 
| HGNCid = 5295
Research indicates that some suicide victims have an abnormally high number of 5-HT<sub>2C</sub> receptors in the prefrontal cortex.<ref name="pmid11282248">{{cite journal | vauthors = Niswender CM, Herrick-Davis K, Dilley GE, Meltzer HY, Overholser JC, Stockmeier CA, Emeson RB, Sanders-Bush E | title = RNA editing of the human serotonin 5-HT2C receptor. alterations in suicide and implications for serotonergic pharmacotherapy | journal = Neuropsychopharmacology | volume = 24 | issue = 5 | pages = 478–91 | date = May 2001 | pmid = 11282248 | doi = 10.1016/S0893-133X(00)00223-2 }}</ref> There is some mixed evidence that [[agomelatine]], a 5-HT<sub>2C</sub> [[receptor antagonist|antagonist]], is an effective [[antidepressant]].<ref name="pmid20694073">{{cite journal | vauthors = Eser D, Baghai TC, Möller HJ | title = Agomelatine: The evidence for its place in the treatment of depression | journal = Core Evidence | volume = 4 | issue =  | pages = 171–9 | year = 2010 | pmid = 20694073 | pmc = 2899775 | doi = 10.2147/CE.S6005 }}</ref> Antagonism of 5-HT<sub>2C</sub> receptors by agomelatine results in an increase of dopamine and norepinephrine activity in the frontal cortex. Conversely, many [[Selective serotonin reuptake inhibitor|SSRIs]] (but not [[fluoxetine]], which is a 5-HT2C antagonist<ref name="pmid9050900" />) indirectly stimulate 5-HT<sub>2C</sub> activity by increasing levels of serotonin in the [[synapse]] although the delayed mood elevation that is usually typical of SSRIs is usually paralleled by the downregulation of the 5-HT2C receptors.<ref name="pmid16269190">{{cite journal | vauthors = Berg KA, Harvey JA, Spampinato U, Clarke WP | title = Physiological relevance of constitutive activity of 5-HT2A and 5-HT2C receptors | journal = Trends in Pharmacological Sciences | volume = 26 | issue = 12 | pages = 625–30 | date = December 2005 | pmid = 16269190 | doi = 10.1016/j.tips.2005.10.008 }}</ref> Many [[atypical antipsychotic]]s block 5-HT<sub>2C</sub> receptors, but their clinical use is limited by multiple undesirable actions on various [[neurotransmitter]]s and [[Receptor (biochemistry)|receptors]]. Fluoxetine acts as a direct 5-HT<sub>2C</sub> antagonist in addition to inhibiting serotonin [[reuptake]], however, the clinical significance of this action is variable.<ref name="pmid9050900">{{cite journal | vauthors = Ni YG, Miledi R | title = Blockage of 5HT2C serotonin receptors by fluoxetine (Prozac) | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 94 | issue = 5 | pages = 2036–40 | date = March 1997 | pmid = 9050900 | pmc = 20038 | doi = 10.1073/pnas.94.5.2036 | bibcode = 1997PNAS...94.2036N }}</ref>
| Symbol = HTR2C
 
| AltSymbols =; 5-HT2C; HTR1C
An overactivity of 5-HT<sub>2C</sub> receptors may contribute to depressive and anxiety symptoms in a certain population of patients. Activation of 5-HT<sub>2C</sub> by serotonin is responsible for many of the negative [[side effect]]s of SSRI and [[Serotonin–norepinephrine reuptake inhibitor|SNRI]] medications, such as [[sertraline]], [[paroxetine]], [[venlafaxine]], and others. Some of the initial anxiety caused by SSRIs is due to excessive signalling at 5-HT<sub>2C</sub>. Over a period of 1–2 weeks, the receptor begins to [[downregulate]], along with the downregulation of 5-HT<sub>2A</sub>, 5-HT1<sub>A</sub>, and other serotonin receptors. This downregulation parallels the onset of the clinical benefits of SSRIs. 5-HT<sub>2C</sub> receptors exhibit [[constitutive activity]] ''in vivo'', and may retain the ability to influence neurotransmission in the absence of ligand occupancy. Thus, 5-HT<sub>2C</sub> receptors do not require binding by a [[Ligand (biochemistry)|ligand]] (serotonin) in order to exhibit influence on neurotransmission. [[Inverse agonist]]s may be required to fully extinguish 5-HT<sub>2C</sub> constitutive activity, and may prove useful in the treatment of 5-HT<sub>2C</sub>-mediated conditions in the absence of typical serotonin activity.<ref name="pmid16269190"/> In addition to the evidence for a role of 5-HT<sub>2C</sub> receptor stimulation in depressive symptoms there also is evidence that activation of 5-HT<sub>2C</sub> receptors may have beneficial effects upon certain aspects of depression, one group of researchers found that direct stimulation of 5-HT<sub>2C</sub> receptors with a 5-HT<sub>2C</sub> agonist reduced cognitive deficits in mice with a [[tryptophan hydroxylase 2|TPH2]] loss-of-function mutation.<ref name="pmid24196946">{{cite journal | vauthors = Del'Guidice T, Lemay F, Lemasson M, Levasseur-Moreau J, Manta S, Etievant A, Escoffier G, Doré FY, Roman FS, Beaulieu JM | title = Stimulation of 5-HT2C receptors improves cognitive deficits induced by human tryptophan hydroxylase 2 loss of function mutation | journal = Neuropsychopharmacology | volume = 39 | issue = 5 | pages = 1125–34 | date = April 2014 | pmid = 24196946 | doi = 10.1038/npp.2013.313 | pmc=3957106}}</ref>
| OMIM = 312861
 
| ECnumber =
5-HT<sub>2C</sub> receptors mediate the release and increase of extracellular dopamine in response to many drugs,<ref name="pmid16475959">{{cite journal | vauthors = Esposito E | title = Serotonin-dopamine interaction as a focus of novel antidepressant drugs | journal = Current Drug Targets | volume = 7 | issue = 2 | pages = 177–85 | date = February 2006 | pmid = 16475959 | doi = 10.2174/138945006775515455 }}</ref><ref name="pmid17017968">{{cite journal | vauthors = Bubar MJ, Cunningham KA | title = Serotonin 5-HT2A and 5-HT2C receptors as potential targets for modulation of psychostimulant use and dependence | journal = Current Topics in Medicinal Chemistry | volume = 6 | issue = 18 | pages = 1971–85 | year = 2006 | pmid = 17017968 | doi = 10.2174/156802606778522131 }}</ref> including [[caffeine]], [[nicotine]], [[amphetamine]], [[morphine]], [[cocaine]], and others. 5-HT<sub>2C</sub> antagonism increases dopamine release in response to reinforcing drugs, and many dopaminergic stimuli. Feeding, social interaction, and sexual activity all release dopamine subject to inhibition of 5-HT<sub>2C</sub>.  Increased 5-HT<sub>2C</sub> expression reduces dopamine release in both the presence and absence of stimuli.
| Homologene = 20242
 
| MGIid = 96281
Conditions that increase [[cytokine]] levels in the human body may have potential to raise 5-HT<sub>2C</sub> gene expression in the brain. This could possibly comprise a link between viral infections and associated depression. Cytokine therapy has been shown to increase 5-HT<sub>2C</sub> gene expression, resulting in increased activity of 5-HT<sub>2C</sub> receptors in the brain {{Citation needed|date=August 2015}}.
| GeneAtlas_image1 = PBB_GE_HTR2C_211479_s_at_tn.png
 
| GeneAtlas_image2 = PBB_GE_HTR2C_207307_at_tn.png
== Endocrinology ==
| Function = {{GNF_GO|id=GO:0001584 |text = rhodopsin-like receptor activity}} {{GNF_GO|id=GO:0004872 |text = receptor activity}} {{GNF_GO|id=GO:0004993 |text = serotonin receptor activity}} {{GNF_GO|id=GO:0005515 |text = protein binding}}  
Serotonin is involved in basal and stress-induced regulation of [[hypothalamic|hypothalamus]] and [[pituitary|pituitary gland]] hormones such as [[prolactin]], adrenocorticotropic hormone ([[ACTH]]), [[vasopressin]] and [[oxytocin]], mainly via actions of receptor subtypes 5-HT<sub>2A</sub> and 5-HT<sub>2C</sub>.<ref name="pmid18208678">{{cite journal | vauthors = Jørgensen HS | title = Studies on the neuroendocrine role of serotonin | journal = Danish Medical Bulletin | volume = 54 | issue = 4 | pages = 266–88 | date = November 2007 | pmid = 18208678 | doi =  }}</ref> Therefore, the 5-HT<sub>2C</sub> receptor is a significant modulator of the hypothalamic–pituitary–adrenal axis ([[Hypothalamic–pituitary–adrenal axis|HPA axis]]).<ref name="pmid17596444">{{cite journal | vauthors = Heisler LK, Pronchuk N, Nonogaki K, Zhou L, Raber J, Tung L, Yeo GS, O'Rahilly S, Colmers WF, Elmquist JK, Tecott LH | title = Serotonin activates the hypothalamic-pituitary-adrenal axis via serotonin 2C receptor stimulation | journal = The Journal of Neuroscience | volume = 27 | issue = 26 | pages = 6956–64 | date = June 2007 | pmid = 17596444 | doi = 10.1523/JNEUROSCI.2584-06.2007 }}</ref> The HPA axis is the main controller of acute [[sympathetic nervous system|sympathetic]] stress responses related to [[fight-or-flight response]]. Prolonged activation and disturbances of the HPA axis contribute to depressive and anxiety symptoms seen in many psychopathological conditions.
| Component = {{GNF_GO|id=GO:0005887 |text = integral to plasma membrane}} {{GNF_GO|id=GO:0016020 |text = membrane}}  
 
| Process = {{GNF_GO|id=GO:0007165 |text = signal transduction}} {{GNF_GO|id=GO:0007210 |text = serotonin receptor signaling pathway}} {{GNF_GO|id=GO:0007268 |text = synaptic transmission}} {{GNF_GO|id=GO:0007631 |text = feeding behavior}}  
Stimulation of 5-HT<sub>2C</sub> receptors leads to increase of corticotropin releasing hormone ([[corticotropin releasing hormone|CRH]]) and vasopressin mRNA in the [[paraventricular nucleus]] and proopiomelanocortin in the anterior pituitary lobe. In rats, restraint stress (which can produce depressive symptoms if being chronic) induces secretion of prolactin, ACTH, vasopressin and oxytocin which is partially mediated via 5-HT<sub>2C</sub> receptor. Responses during such conditions as dehydration or haemorrhage causes the release oxytocin via serotonergic response that is partly mediated via 5-HT<sub>2C</sub>. In addition, peripheral release of vasopressin involves serotonergic response which is partially mediated via 5-HT<sub>2C</sub>.
| Orthologs = {{GNF_Ortholog_box
 
    | Hs_EntrezGene = 3358
Expression of the 5-HT<sub>2C</sub> receptor in the CNS is modulated by female sex hormones [[estradiol]] and [[progesterone]]. Combination of the hormones decrease the receptor concentration in the [[ventral]] [[hippocampus]] in rats and could thus affect mood.<ref name="pmid11834317">{{cite journal | vauthors = Birzniece V, Johansson IM, Wang MD, Bäckström T, Olsson T | title = Ovarian hormone effects on 5-hydroxytryptamine(2A) and 5-hydroxytryptamine(2C) receptor mRNA expression in the ventral hippocampus and frontal cortex of female rats | journal = Neuroscience Letters | volume = 319 | issue = 3 | pages = 157–61 | date = February 2002 | pmid = 11834317 | doi = 10.1016/S0304-3940(01)02570-8 }}</ref>
    | Hs_Ensembl = ENSG00000147246
 
    | Hs_RefseqProtein = NP_000859
== Genetics ==
    | Hs_RefseqmRNA = NM_000868
 
    | Hs_GenLoc_db =
Many human polymorphisms have been identified influencing the expression of 5-HT<sub>2C</sub>. Significant correlations are suggested, specifically in relation to psychiatric disorders such as depression, OCD, and anxiety-related conditions. Polymorphisms also correlate with susceptibility to a number of conditions including drug abuse and obesity. There are indications that the alternative splicing of the 5-HT<sub>2C</sub> receptor is regulated by a [[Small nucleolar RNA|snoRNA]] called [[Small nucleolar RNA SNORD115|SNORD115]], the deletion of which is associated with [[Prader–Willi syndrome]].<ref name="pmid16357227">{{cite journal | vauthors = Kishore S, Stamm S | title = The snoRNA HBII-52 regulates alternative splicing of the serotonin receptor 2C | journal = Science | volume = 311 | issue = 5758 | pages = 230–2 | date = January 2006 | pmid = 16357227 | doi = 10.1126/science.1118265 | bibcode = 2006Sci...311..230K }}</ref><ref name="pmid18500341">{{cite journal | vauthors = Sahoo T, del Gaudio D, German JR, Shinawi M, Peters SU, Person RE, Garnica A, Cheung SW, Beaudet AL | title = Prader-Willi phenotype caused by paternal deficiency for the HBII-85 C/D box small nucleolar RNA cluster | journal = Nature Genetics | volume = 40 | issue = 6 | pages = 719–21 | date = June 2008 | pmid = 18500341 | pmc = 2705197 | doi = 10.1038/ng.158 }}</ref> As the human gene is located in the X chromosome, males have only one copy of the gene whereas women have two, meaning that mutations in the gene affect the phenotype of men even when the allele would be recessive in nature. As women have two copies of the gene, but only one allele is expressed in each cell, they are a mosaic for polymorphisms, meaning that one genetic variant may be prevalent in one tissue and another variant will be prevalent in a different tissue (as with all other x-linked genetic variations).
    | Hs_GenLoc_chr = X
    | Hs_GenLoc_start = 113724807
    | Hs_GenLoc_end = 114050880
    | Hs_Uniprot = P28335
    | Mm_EntrezGene = 15560
    | Mm_Ensembl = ENSMUSG00000041380
    | Mm_RefseqmRNA = XM_978183
    | Mm_RefseqProtein = XP_983277
    | Mm_GenLoc_db =
    | Mm_GenLoc_chr = X
    | Mm_GenLoc_start = 142208881
    | Mm_GenLoc_end = 142443644
    | Mm_Uniprot = Q8BUB1
  }}
}}
{{CMG}}  
==Overview==
'''5-hydroxytryptamine (serotonin) receptor 2C''', also known as '''HTR2C''', is a [[5-HT2 receptor|5-HT<sub>2</sub> receptor]], but also denotes the human [[gene]] encoding it.
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==Function==
*CNS: anxiety, [[choroid plexus]]: [[cerebrospinal fluid]] (CSF) secretion


==Ligands==
==Ligands==
Numerous (ex-)prescription, illicit and research drugs contain a 5-HT<sub>2C</sub> component in their binding profile, including [[fluoxetine]], [[mianserin]]<!--inverse agonist-->, [[clozapine]], [[agomelatine]], dextro-[[norfenfluramine]]<!--full agonist-->, [[psilocin]], [[2,5-Dimethoxy-4-iodoamphetamine|DOI]]<!--partial agonist-->, α-methyl-serotonin, MK-212, [[1-(3-Chlorophenyl)piperazine|''m''-CPP]]<!--partial agonist-->, FG-7142,<ref name="pmid17138863">{{cite journal | author = Hackler EA, Turner GH, Gresch PJ, Sengupta S, Deutch AY, Avison MJ, Gore JC, Sanders-Bush E | title = 5-Hydroxytryptamine2C receptor contribution to m-chlorophenylpiperazine and N-methyl-beta-carboline-3-carboxamide-induced anxiety-like behavior and limbic brain activation | journal = J. Pharmacol. Exp. Ther. | volume = 320 | issue = 3 | pages = 1023-9 | year = 2007 | pmid = 17138863 | doi = 10.1124/jpet.106.113357 | issn = }}</ref> Ro60-0175<!--agonist-->,<ref name="pmid11399662">{{cite journal | author = Higgins GA, Ouagazzal AM, Grottick AJ | title = Influence of the 5-HT(2C) receptor antagonist SB242,084 on behaviour produced by the 5-HT<sub>2</sub> agonist Ro60-0175 and the indirect 5-HT agonist dexfenfluramine | journal = Br. J. Pharmacol. | volume = 133 | issue = 4 | pages = 459-66 | year = 2001 | pmid = 11399662 | doi = 10.1038/sj.bjp.0704082 | issn = }}</ref> [[mesulergine]], [[metergoline]], [[ritanserin]], [[methiothepin]], 5-methoxy[[gramine]]<!--silent antagonist-->, and many more.<ref name="pmid17017967">{{cite journal | author = Lacivita E, Leopoldo M | title = Selective agents for serotonin 2C (5-HT<sub>2C</sub>) receptor | journal = Curr Top Med Chem | volume = 6 | issue = 18 | pages = 1927-70 | year = 2006 | pmid = 17017967 | doi = 10.2174/156802606778522168 | issn = }}</ref> Some compounds with a more pronounced selectivity for the 5-HT<sub>2C</sub> receptor subtype are listed below. Note, that in the following context the term "functional selectivity" does not refer to differentiation of transductional pathways.
First allosteric modulators were developed in 2018.<ref name="pmid29620897">{{cite journal |vauthors=Wild CT, Miszkiel JM, Wold EA, Soto CA, Ding C, Hartley RM, White MA, Anastasio NC, Cunningham KA, Zhou J |title=Design, Synthesis, and Characterization of 4-Undecylpiperidine-2-carboxamides as Positive Allosteric Modulators of the Serotonin (5-HT) 5-HT2C Receptor |journal=J. Med. Chem. |volume= |issue= |pages= |date=April 2018 |pmid=29620897 |doi=10.1021/acs.jmedchem.8b00401 |url=}}</ref>
 
===Agonists===
{{Main article|5-HT2C receptor agonist}}
 
* [[A-372,159]]
* [[AL-38022A]]
* [[CP-809,101]]
* [[CPD-1]] <ref name="pmid28588509">{{cite journal |vauthors = Rodriguez MM, Overshiner C, Leander JD, Li X, Morrow D, Conway RG, Nelson DL, Briner K, Witkin JM |title = Behavioral Effects of a Novel Benzofuranyl-Piperazine Serotonin-2C Receptor Agonist Suggest a Potential Therapeutic Application in the Treatment of Obsessive-Compulsive Disorder |journal = Front Psychiatry |volume = 8 |issue= |pages = 89 |year = 2017 |pmid = 28588509 |pmc = 5438973 |doi = 10.3389/fpsyt.2017.00089 }}</ref>
* [[Fenfluramine]]
* [[Lisuride]]
* [[Lorcaserin]]
* [[Mesulergine]]
* [[MK-212]]
* [[Naphthylisopropylamine]]
* [[Norfenfluramine]]
* [[Org 12,962]]
* [[ORG-37,684]]
* [[Oxaflozane]]
* [[PNU-22394]]
* [[PNU-181731]]
* [[Psychedelic drug|Psychedelic]]s
** [[Lysergamide]]s ([[Lysergic acid diethylamide|LSD]], etc.)
** [[Substituted phenethylamine|Phenethylamine]]s ([[2,5-Dimethoxy-4-bromophenethylamine|2C-B]], [[2,5-Dimethoxy-4-iodoamphetamine|DOI]], [[2,5-Dimethoxy-4-methylamphetamine|DOM]], [[Mescaline]], etc.)
** [[Piperazine]]s ([[Meta-Chlorophenylpiperazine|mCPP]], [[TFMPP]], etc.)
** [[Tryptamine]]s ([[5-MeO-DMT]], [[Bufotenin]], [[Dimethyltryptamine|DMT]], [[Psilocin]], etc.)
* [[Ro60-0175]]
* [[Vabicaserin]]
* [[WAY-629]]
* [[WAY-161,503]]
* [[WAY-163,909]]
* [[YM-348]]


=== Agonists ===
====Partial agonists====
*YM348: potent, [[full agonist]], high [[Dissociation constant#Protein-Ligand binding|affinity]], high functional selectivity, orally active<ref name="pmid14709324">{{cite journal | author = Kimura Y, Hatanaka K, Naitou Y, Maeno K, Shimada I, Koakutsu A, Wanibuchi F, Yamaguchi T | title = Pharmacological profile of YM348, a novel, potent and orally active 5-HT<sub>2C</sub> receptor agonist | journal = Eur. J. Pharmacol. | volume = 483 | issue = 1 | pages = 37-43 | year = 2004 | pmid = 14709324 | doi = 10.1016/j.ejphar.2003.10.004 | issn = }}</ref><ref name="pmid18035544">{{cite journal | author = Shimada I, Maeno K, Kazuta K, Kubota H, Kimizuka T, Kimura Y, Hatanaka K, Naitou Y, Wanibuchi F, Sakamoto S, Tsukamoto S | title = Synthesis and structure-activity relationships of a series of substituted 2-(1H-furo[2,3-g]indazol-1-yl)ethylamine derivatives as 5-HT<sub>2C</sub> receptor agonists | journal = Bioorg. Med. Chem. | volume = 16 | issue = 4 | pages = 1966-82 | year = 2008 | pmid = 18035544 | doi = 10.1016/j.bmc.2007.10.100 | issn = }}</ref>
* [[Aripiprazole]]


*(5a''R'',9''R'')-2-[(cyclopropylmethoxy)methyl]-5,5a,6,7,8,9-hexahydro-9-methyl-pyrido[3′,2′:4,5]pyrrolo[1,2-a]pyrazine: potent, full agonist with an outstanding selectivity profile<ref name="pmid16361098">{{cite journal | author = Richter HG, Adams DR, Benardeau A, Bickerdike MJ, Bentley JM, Blench TJ, Cliffe IA, Dourish C, Hebeisen P, Kennett GA, Knight AR, Malcolm CS, Mattei P, Misra A, Mizrahi J, Monck NJ, Plancher JM, Roever S, Roffey JR, Taylor S, Vickers SP | title = Synthesis and biological evaluation of novel hexahydro-pyrido[3',2':4,5]pyrrolo[1,2-a]pyrazines as potent and selective 5-HT<sub>2C</sub> receptor agonists | journal = Bioorg. Med. Chem. Lett. | volume = 16 | issue = 5 | pages = 1207-11 | year = 2006 | pmid = 16361098 | doi = 10.1016/j.bmcl.2005.11.083 | issn = }}</ref>
===Antagonists===
* [[Agomelatine]]
* [[6-Chloro-5-ethoxy-N-(pyridin-2-yl)indoline-1-carboxamide|CEPC]]<ref>McCorvy JD, Harland AA, Maglathlin R, Nichols DE. A 5-HT(2C) receptor antagonist potentiates a low dose amphetamine-induced conditioned place preference. ''Neuroscience Letters''. 2011 November 7;505(1):10-3. {{PMID|21827831}}</ref>
* [[Eltoprazine]]
* [[Etoperidone]]
* [[Fluoxetine]]
* [[FR-260,010]]
* [[Lu AA24530]]
* [[Methysergide]]
* [[Nefazodone]]
* [[Norfluoxetine]]
* [[O-Desmethyltramadol]]
* [[Promethazine]]
* [[RS-102,221]]
* [[SB-200,646]]
* [[SB-221,284]]
* [[SB-242,084]]
* [[SDZ SER-082]]
* [[Tramadol]]
* [[Trazodone]]


*(''R'')-9-ethyl-1,3,4,10b-tetrahydro-7-trifluoromethylpyrazino[2,1-a]isoindol-6(2''H'')-one: agonist, >300-fold functional selectivity over 5-HT<sub>2B</sub> and >70-fold over 5-HT<sub>2A</sub><ref name="pmid17315987">{{cite journal | author = Wacker DA, Varnes JG, Malmstrom SE, Cao X, Hung CP, Ung T, Wu G, Zhang G, Zuvich E, Thomas MA, Keim WJ, Cullen MJ, Rohrbach KW, Qu Q, Narayanan R, Rossi K, Janovitz E, Lehman-McKeeman L, Malley MF, Devenny J, Pelleymounter MA, Miller KJ, Robl JA | title = Discovery of (R)-9-ethyl-1,3,4,10b-tetrahydro-7-trifluoromethylpyrazino[2,1-a]isoindol- 6(2H)-one, a selective, orally active agonist of the 5-HT<sub>2C</sub> receptor | journal = J. Med. Chem. | volume = 50 | issue = 6 | pages = 1365-79 | year = 2007 | pmid = 17315987 | doi = 10.1021/jm0612968 | issn = }}</ref>
===Inverse agonists===
* [[Antidepressants]] {{Citation needed |date=March 2017}}
** [[Tricyclic antidepressant|Tricyclic]]s ([[Amitriptyline]], [[Clomipramine]], [[Imipramine]], [[Nortriptyline]], [[Doxepin]], etc.)
** [[Tetracyclic antidepressant|Tetracyclic]]s  ([[Mirtazapine]], [[Mianserin]], [[Amoxapine]], etc.)
* [[Antihistamine]]s ([[Cyproheptadine]], [[Hydroxyzine]], [[Latrepirdine]], etc.)
* [[Antipsychotic]]s
** [[Typical antipsychotic|Typical]]s ([[Chlorpromazine]], [[Fluphenazine]], [[Loxapine]], [[Thioridazine]], etc.)
** [[Atypical antipsychotic|Atypical]]s ([[Clozapine]], [[Olanzapine]], [[Quetiapine]], [[Risperidone]], [[Ziprasidone]], etc.)
* [[Cinanserin]]
* [[Deramciclane]]
* [[Ketanserin]]
* [[LY-53,857]]
* [[Metergoline]]
* [[Methiothepin]]
* [[Pizotifen]]
* [[Ritanserin]]
* [[S-32212]]<ref name="pmid22178753">{{cite journal | vauthors = Dekeyne A, Brocco M, Loiseau F, Gobert A, Rivet JM, Di Cara B, Cremers TI, Flik G, Fone KC, Watson DJ, Papp M, Sharp T, Serres F, Cespuglio R, Olivier B, Chan JS, Lavielle G, Millan MJ | title = S32212, a novel serotonin type 2C receptor inverse agonist/α2-adrenoceptor antagonist and potential antidepressant: II. A behavioral, neurochemical, and electrophysiological characterization | journal = The Journal of Pharmacology and Experimental Therapeutics | volume = 340 | issue = 3 | pages = 765–80 | date = March 2012 | pmid = 22178753 | doi = 10.1124/jpet.111.187534 }}</ref>
* [[SB-206,553]]
* [[SB-228,357]]
* [[SB-243,213]]
* [[SB-242,084]]


*Lorcaserin: full agonist, fair selectivity profile<ref name="pmid18252809">{{cite journal | author = Thomsen WJ, Grottick AJ, Menzaghi F, Reyes-Saldana H, Espitia S, Yuskin D, Whelan K, Martin M, Morgan M, Chen W, Al-Shama H, Smith B, Chalmers D, Behan D | title = Lorcaserin, A Novel Selective Human 5-HT<sub>2C</sub> Agonist: In Vitro and In Vivo Pharmacological Characterization | journal = J. Pharmacol. Exp. Ther. | volume = | issue = | pages = | year = 2008 | pmid = 18252809 | doi = 10.1124/jpet.107.133348 | issn = }}</ref><ref name="pmid15713408">{{cite journal | author = Smith BM, Smith JM, Tsai JH, Schultz JA, Gilson CA, Estrada SA, Chen RR, Park DM, Prieto EB, Gallardo CS, Sengupta D, Thomsen WJ, Saldana HR, Whelan KT, Menzaghi F, Webb RR, Beeley NR | title = Discovery and SAR of new benzazepines as potent and selective 5-HT<sub>2C</sub> receptor agonists for the treatment of obesity | journal = Bioorg. Med. Chem. Lett. | volume = 15 | issue = 5 | pages = 1467-70 | year = 2005 | pmid = 15713408 | doi = 10.1016/j.bmcl.2004.12.080 | issn = }}</ref><ref name="pmid18039773">{{cite journal | author = Lam DD, Przydzial MJ, Ridley SH, Yeo GS, Rochford JJ, O'Rahilly S, Heisler LK | title = Serotonin 5-HT2C Receptor Agonist Promotes Hypophagia via Downstream Activation of Melanocortin 4 Receptors | journal = Endocrinology | volume = 149 | issue = 3 | pages = 1323-8 | year = 2008 | pmid = 18039773 | doi = 10.1210/en.2007-1321 | issn = }}</ref>
== Interactions ==


=== Antagonists ===
The 5-HT<sub>2C</sub> receptor has been shown to [[Protein-protein interaction|interact]] with [[MPDZ]].<ref name="pmid11150294">{{cite journal | vauthors = Becamel C, Figge A, Poliak S, Dumuis A, Peles E, Bockaert J, Lubbert H, Ullmer C | title = Interaction of serotonin 5-hydroxytryptamine type 2C receptors with PDZ10 of the multi-PDZ domain protein MUPP1 | journal = The Journal of Biological Chemistry | volume = 276 | issue = 16 | pages = 12974–82 | date = April 2001 | pmid = 11150294 | doi = 10.1074/jbc.M008089200 }}</ref><ref name="pmid9537516">{{cite journal | vauthors = Ullmer C, Schmuck K, Figge A, Lübbert H | title = Cloning and characterization of MUPP1, a novel PDZ domain protein | journal = FEBS Letters | volume = 424 | issue = 1–2 | pages = 63–8 | date = March 1998 | pmid = 9537516 | doi = 10.1016/S0014-5793(98)00141-0 }}</ref>
*FR260010: [[silent antagonist]], high affinity, selective over 5-HT<sub>2A</sub> and many other receptors; orally active.<ref name="pmid17074317">{{cite journal | author = Harada K, Aota M, Inoue T, Matsuda R, Mihara T, Yamaji T, Ishibashi K, Matsuoka N | title = Anxiolytic activity of a novel potent serotonin 5-HT<sub>2C</sub> receptor antagonist FR260010: a comparison with diazepam and buspirone | journal = Eur. J. Pharmacol. | volume = 553 | issue = 1-3 | pages = 171-84 | year = 2006 | pmid = 17074317 | doi = 10.1016/j.ejphar.2006.09.042 | issn = }}</ref>


*RS-102221: silent antagonist, 100-fold selectivity compared to the 5-HT<sub>2A</sub> and -HT<sub>2B</sub> receptor subtypes<ref name="pmid9225287">{{cite journal | author = Bonhaus DW, Weinhardt KK, Taylor M, DeSouza A, McNeeley PM, Szczepanski K, Fontana DJ, Trinh J, Rocha CL, Dawson MW, Flippin LA, Eglen RM | title = RS-102221: a novel high affinity and selective, 5-HT<sub>2C</sub> receptor antagonist | journal = Neuropharmacology | volume = 36 | issue = 4-5 | pages = 621-9 | year = 1997 | pmid = 9225287 | doi = 10.1016/S0028-3908(97)00049-X | issn = }}</ref>
== RNA editing ==


===Mixed response===
5HT2CR pre-mRNA can be the subject of [[RNA editing]].<ref name="pmid9153397">{{cite journal | vauthors = Burns CM, Chu H, Rueter SM, Hutchinson LK, Canton H, Sanders-Bush E, Emeson RB | title = Regulation of serotonin-2C receptor G-protein coupling by RNA editing | journal = Nature | volume = 387 | issue = 6630 | pages = 303–8 | date = May 1997 | pmid = 9153397 | doi = 10.1038/387303a0 | bibcode = 1997Natur.387..303B }}</ref> It is the only serotonin receptor as well as the only member of the large family of 7 transmembrane receptors (7TMRs) known to be edited. Different levels of editing result in a variety of effects on receptor function.
A more extensive examination on [[signal transduction]] was carried out for
*SB-243213: high affinity, >100-fold selectivity over a wide range of neurotransmitter receptors, enzymes and [[ion channel]]s; long duration of action in vivo (>8 h); [[anxiolytic]]-like effects.<ref name="pmid11489455">{{cite journal | author = Wood MD, Reavill C, Trail B, Wilson A, Stean T, Kennett GA, Lightowler S, Blackburn TP, Thomas D, Gager TL, Riley G, Holland V, Bromidge SM, Forbes IT, Middlemiss DN | title = SB-243213; a selective 5-HT<sub>2C</sub> receptor inverse agonist with improved anxiolytic profile: lack of tolerance and withdrawal anxiety | journal = Neuropharmacology | volume = 41 | issue = 2 | pages = 186-99 | year = 2001 | pmid = 11489455 | doi = 10.1016/S0028-3908(01)00054-5 | issn = }}</ref> ''[[Inverse agonist]]'' for the [[phospholipase A2|PLA2]] response, for [[GTPgammaS]] binding, for reduction of constitutive desensitization, and for enhancement of dopamine release in the rat [[nucleus accumbens]]. ''Silent antagonist'' for the [[phospholipase C|PLC]] cascade.<ref name="pmid16807362">{{cite journal | author = Berg KA, Navailles S, Sanchez TA, Silva YM, Wood MD, Spampinato U, Clarke WP | title = Differential effects of 5-methyl-1-{[2-[(2-methyl-3-pyridyl)oxyl]-5-pyridyl]carbamoyl}-6-trifluoromethylindone (SB 243213) on 5-hydroxytryptamine (2C) receptor-mediated responses | journal = J. Pharmacol. Exp. Ther. | volume = 319 | issue = 1 | pages = 260-8 | year = 2006 | pmid = 16807362 | doi = 10.1124/jpet.106.104448 | issn = }}</ref> (See also [[functional selectivity]]).


==Receptor regulation==
=== Type ===
Agonists promote 5-HT<sub>2C</sub> receptor [[internalization (cell biology)|internalization]] leading to [[tachyphylaxis]].<ref name="pmid15113845">{{cite journal | author = Schlag BD, Lou Z, Fennell M, Dunlop J | title = Ligand dependency of 5-hydroxytryptamine 2C receptor internalization | journal = J. Pharmacol. Exp. Ther. | volume = 310 | issue = 3 | pages = 865-70 | year = 2004 | pmid = 15113845 | doi = 10.1124/jpet.104.067306 | issn = }}</ref>


==See also==
The type of RNA editing that occurs in the [[pre-mRNA]] of the 5HT2CR is Adenosine to Inosine (A to I) editing.
 
A to I RNA editing is catalyzed by a family of [[adenosine deaminase]]s acting on RNA (ADARs) that specifically recognize adenosines within double-stranded regions of pre-mRNAs and deaminate them to [[inosine]]. [[Inosine]]s are recognised as [[guanosine]] by the cells translational machinery. There are three members of the ADAR family ADARs 1-3 with [[ADAR|ADAR1]] and [[ADARB1|ADAR2]] being the only enzymatically active members. [[ADARB2|ADAR3]] is thought to have a regulatory role in the brain. ADAR1 and ADAR2 are widely expressed in tissues while ADAR3 is restricted to the brain. The double stranded regions of RNA are formed by base-pairing between residues in the close to region of the editing site with residues usually in a neighboring intron but can be an exonic sequence. The region that base pairs with the editing region is known as an Editing Complementary Sequence (ECS).
 
ADARs bind interact directly with the dsRNA substrate via their double stranded RNA binding domains. If an editing site occurs within a coding sequence, it can result in a codon change. This can lead to translation of a protein isoform due to a change in its primary protein structure. Therefore, editing can also alter protein function.  A to I editing occurs in a non coding RNA sequences such as [[introns]], [[untranslated regions]] (UTRs), [[LINEs]], SINEs ( especially Alu repeats) The function of A to I editing in these regions is thought to involve creation of splice sites and retention of RNAs in the nucleus amongst others.
 
=== Location ===
 
Editing occurs in 5 different closely located sites within exon 5, which corresponds to the second intracellular loop of the final protein. The sites are known as A, B, C′ (previously called E), C and D, and are predicted to occur within amino acid positions 156, 158 and 160. Several codon changes can occur due to A-to-I editing at these sites. Thirty-two different mRNA variants can occur leading to 24 different protein isoforms.
 
#An Isoleucine to Valine  (I/V) at amino acid position 157,161.
#An Isoleucine to a Methionine(I/M) at amino acid position 157
#An Aspartate to a Serine (N/S)at 159
#An Aspartate to Asparagine(N/D) at 159
#An Asparagine to a Glycine(N/G) at 159.
 
These codon changes which can occur due to A to I editing at these sites can lead to a maximum of 32 different mRNA variants leading to 24 different protein isoforms. The number of protein isoforms is less than 32 since some amino acids are encoded by more than one codon.<ref name="pmid10432493">{{cite journal | vauthors = Fitzgerald LW, Iyer G, Conklin DS, Krause CM, Marshall A, Patterson JP, Tran DP, Jonak GJ, Hartig PR | title = Messenger RNA editing of the human serotonin 5-HT2C receptor | journal = Neuropsychopharmacology | volume = 21 | issue = 2 Suppl | pages = 82S–90S | date = August 1999 | pmid = 10432493 | doi = 10.1016/S0893-133X(99)00004-4 }}</ref> Another editing site, site F has also been located in the exon complementary sequence (ECS) of intron 5.<ref name="pmid15087490">{{cite journal | vauthors = Flomen R, Knight J, Sham P, Kerwin R, Makoff A | title = Evidence that RNA editing modulates splice site selection in the 5-HT2C receptor gene | journal = Nucleic Acids Research | volume = 32 | issue = 7 | pages = 2113–22 | year = 2004 | pmid = 15087490 | pmc = 407821 | doi = 10.1093/nar/gkh536 }}</ref> The ECS required for formation of double stranded RNA structure is found within intron 5.<ref name="pmid9153397" />
 
=== Conservation ===
 
RNA editing of this receptor occurs at 4 locations in the rat.<ref name="pmid9153397" /> Editing also occurs in the mouse.<ref name="pmid16580757">{{cite journal | vauthors = Hackler EA, Airey DC, Shannon CC, Sodhi MS, Sanders-Bush E | title = 5-HT(2C) receptor RNA editing in the amygdala of C57BL/6J, DBA/2J, and BALB/cJ mice | journal = Neuroscience Research | volume = 55 | issue = 1 | pages = 96–104 | date = May 2006 | pmid = 16580757 | doi = 10.1016/j.neures.2006.02.005 }}</ref> The initial demonstration of RNA editing in rat.<ref name="pmid9153397"/> The predominant isoform in rat brain is VNV which differs from the most common type found in humans.<ref name="pmid9153397" /><ref name="pmid10092629">{{cite journal | vauthors = Niswender CM, Copeland SC, Herrick-Davis K, Emeson RB, Sanders-Bush E | title = RNA editing of the human serotonin 5-hydroxytryptamine 2C receptor silences constitutive activity | journal = The Journal of Biological Chemistry | volume = 274 | issue = 14 | pages = 9472–8 | date = April 1999 | pmid = 10092629 | doi = 10.1074/jbc.274.14.9472 }}</ref> The editing complementary sequence is known to be conserved across Mammalia.
 
=== Regulation ===
 
The 5-HT<sub>2c</sub> receptor is the only serotonin receptor edited despite its close sequence similarities to other family members.<ref name="pmid10092629" /> 5HT2CR is different due to possessing an imperfect inverted repeat at the end of exon 5 and the beginning of intron 5 allowing formation of an RNA duplex producing the dsRNA required by ADARs for editing. Disruption of this inverted repeat was demonstrated to cease all editing.<ref name="pmid9153397"/> The different 5HT2CR mRNA isoforms are expressed differently throughout the brain, yet not all of the 24 have been detected perhaps due to tissue specific expression or low frequency editing of a particular type. Those isoforms that are not expressed at all or at a very low frequency are linked by being edited only at site C' and/or site B but not at site A. Some examples of differences in frequency of editing and site edited in different parts of the human brain of 5HT2CR include low frequency of editing in cerebellum and nearly all editing is at site D while in the hippocampus editing frequency is higher with site A being the main editing site. Site C' is only found edited in the thalamus. The most common isoform in human brain is the VSV isoform.<ref name="pmid10432493" /><ref name="pmid10092629" /><ref name="pmid10693963">{{cite journal | vauthors = Wang Q, O'Brien PJ, Chen CX, Cho DS, Murray JM, Nishikura K | title = Altered G protein-coupling functions of RNA editing isoform and splicing variant serotonin2C receptors | journal = Journal of Neurochemistry | volume = 74 | issue = 3 | pages = 1290–300 | date = March 2000 | pmid = 10693963 | doi = 10.1046/j.1471-4159.2000.741290.x }}</ref>
 
Mice knock out and other studies have been used to determine which ADAR enzyme are involved in editing. Editing at A and B sites has been demonstrated to be due to ADAR1 editing.<ref name="pmid15093687">{{cite journal | vauthors = Yang W, Wang Q, Kanes SJ, Murray JM, Nishikura K | title = Altered RNA editing of serotonin 5-HT2C receptor induced by interferon: implications for depression associated with cytokine therapy | journal = Brain Research. Molecular Brain Research | volume = 124 | issue = 1 | pages = 70–8 | date = April 2004 | pmid = 15093687 | doi = 10.1016/j.molbrainres.2004.02.010 }}</ref><ref name="pmid16082172">{{cite journal | vauthors = Sukma M, Tohda M, Watanabe H, Matsumoto K | title = The mRNA expression differences of RNA editing enzymes in differentiated and undifferentiated NG108-15 cells | journal = Journal of Pharmacological Sciences | volume = 98 | issue = 4 | pages = 467–70 | date = August 2005 | pmid = 16082172 | doi = 10.1254/jphs.SC0050074 }}</ref><ref name="pmid15492466">{{cite journal | vauthors = Tohda M, Sukma M, Watanabe H | title = RNA editing and short variant of serotonin 2C receptor mRNA in neuronally differentiated NG108-15 cells | journal = Journal of Pharmacological Sciences | volume = 96 | issue = 2 | pages = 164–9 | date = October 2004 | pmid = 15492466 | doi = 10.1254/jphs.FP0040227 }}</ref> Also since ADAR1 expression is increased in response to the presence of interferon α,  it was also observed that editing at A and B sites was also increased because of this.<ref name="pmid15093687" /> C' and D sites require ADAR2 and editing is decreased by the presence of ADAR1 with editing of C' site only observed in ADAR1 double knock out mice.<ref name="pmid14615479">{{cite journal | vauthors = Hartner JC, Schmittwolf C, Kispert A, Müller AM, Higuchi M, Seeburg PH | title = Liver disintegration in the mouse embryo caused by deficiency in the RNA-editing enzyme ADAR1 | journal = The Journal of Biological Chemistry | volume = 279 | issue = 6 | pages = 4894–902 | date = February 2004 | pmid = 14615479 | doi = 10.1074/jbc.M311347200 }}</ref> The C site has been shown to be mainly edited by ADAR2 but in presence of upregulated expression of ADAR1, there was an increase in editing of this site and the enzymes presence can also result in limited editing in ADAR 2 knock out mice.<ref name="pmid15093687" /><ref name="pmid14615479" /> This demonstrates that there must be some form interaction between the two A to I editing enzymes. Also such interactions and tissue specific expression of ADARs interaction may explain the variety in editing patterns in different regions of the brain.
 
====Consequences====
 
Second, the editing pattern controls the amount of the 5-HT2CR mRNA that leads to the expression of full-length protein through the modulation of alternative splice site selection 76,77. Among three alternative splice donor sites (GU1 to GU3; Fig. 4C), GU2 is the only site that forms the mature mRNA to produce the functional, full-length 5-HT2CR protein. Unedited pre-mRNAs tend to be spliced at the GU1 site, resulting in the truncated, non-functional protein if translated 76,77. However, most pre-mRNAs edited at more than one position are spliced at GU2 77. Thus, when editing is inefficient, increased splicing at GU1 may act as a control mechanism to decrease biosynthesis of the 5-HT2CR-INI and thereby limit serotonin response. Third, RNA editing controls the ultimate physiological output of constitutively active receptors by affecting the cell surface expression of the 5-HT2CR. The 5-HT2CR-VGV, which displays the lowest level of constitutive activity, is fully expressed at the cell surface under basal conditions and is rapidly internalized in the presence of agonist 78. In contrast, the 5-HT2CR-INI is constitutively internalized and accumulates in endosomes 78.
 
'''Structure'''
 
As mentioned editing results in several codon changes.The editing sites are found in the second intracellular domain of the protein which is also the receptors G protein coupling domain.Therefore, editing of these sites can affect the affinity of the receptor for G protein binding.<ref name="pmid9153397"/>
 
'''Function'''
 
Editing results in reduced affinity for specific G proteins which in turn affects internal signalling via second messengers (Phospholipase C signalling system). The fully edited isoform, VGV, considerably reduces 5-HT potency, G-protein coupling and agonist binding, compared to the unedited protein isoform, INI. 72-76. Most evidence for the effect of editing on function comes from downstream measurements of receptor activity, radio ligand binding and functional studies.Inhibitory effects are linked to the extent of editing.Those isoforms with a higher level of editing require higher levels of serotonin to activate the phospholipase c pathway. Unedited INI form has a greater tendency to isomerise to an active form which can more easily interact with G proteins. This indicates that RNA editing here may be a mechanism for regulating neuronal excitability by stabilising receptor signalling.<ref name="pmid9153397" /><ref name="pmid10092629"/>
 
Editing is also thought to function in cell surface expression of the receptor subtype. The fully edited VGV, which has the lowest level of constitutive activity, is fully expressed at the cell surface while the non-edited INI is internalised and accumulates in endosome.<ref name="pmid14602721">{{cite journal | vauthors = Marion S, Weiner DM, Caron MG | title = RNA editing induces variation in desensitization and trafficking of 5-hydroxytryptamine 2c receptor isoforms | journal = The Journal of Biological Chemistry | volume = 279 | issue = 4 | pages = 2945–54 | date = January 2004 | pmid = 14602721 | doi = 10.1074/jbc.M308742200 }}</ref>
 
Editing is also thought to influence splicing. Three different spliced isoforms of the receptor exist. Editing regulates the amount of 5HT2CR mRNA which leads to translation of the full length protein selection of alternative splice sites. t76,77. These splice sites are termed Gu1, Gu2, GU3. Only GU2 site splicing results in translation of the full length receptor while editing at GU1 is known to result in translation of a truncated protein. This is thought to be a regulatory mechanism to decrease the amount of unedited isoform INI to limit serotonin response when editing is inefficient. Most of the pre-mRNAs which are edited are spliced at the GU2 site.<ref name="pmid15087490" /><ref name="pmid10693963"/>
 
'''Dysregulation'''
 
Serotonin family of receptors are often linked to pathology of several human mental conditions such as Schizophrenia, anxiety, Bipolar disorder and major depression.<ref name="pmid7792930">{{cite journal | vauthors = Baxter G, Kennett G, Blaney F, Blackburn T | title = 5-HT2 receptor subtypes: a family re-united? | journal = Trends in Pharmacological Sciences | volume = 16 | issue = 3 | pages = 105–10 | date = March 1995 | pmid = 7792930 | doi = 10.1016/S0165-6147(00)88991-9 }}</ref> There have been several experimental investigations into the effects of alternative editing patterns of the 5HT2CR and these conditions with a wide variability in results especially those relating to schizophrenia.<ref name="pmid12853111">{{cite journal | vauthors = Iwamoto K, Kato T | title = RNA editing of serotonin 2C receptor in human postmortem brains of major mental disorders | journal = Neuroscience Letters | volume = 346 | issue = 3 | pages = 169–72 | date = August 2003 | pmid = 12853111 | doi = 10.1016/S0304-3940(03)00608-6 }}</ref> Some studies have noted that there is an increase in RNA editing at site A in depressed suicide victims.<ref name="pmid11282248"/><ref name="pmid12853111" /> E site editing was observed to be increased in individuals suffering from major depression.<ref name="pmid11988167">{{cite journal | vauthors = Gurevich I, Tamir H, Arango V, Dwork AJ, Mann JJ, Schmauss C | title = Altered editing of serotonin 2C receptor pre-mRNA in the prefrontal cortex of depressed suicide victims | journal = Neuron | volume = 34 | issue = 3 | pages = 349–56 | date = April 2002 | pmid = 11988167 | doi = 10.1016/S0896-6273(02)00660-8 }}</ref> In rat models this increase is also observed and can be reversed with fluoxetine with some suggestion that E site editing maybe linked to major depression.<ref name="pmid16005997">{{cite journal | vauthors = Iwamoto K, Nakatani N, Bundo M, Yoshikawa T, Kato T | title = Altered RNA editing of serotonin 2C receptor in a rat model of depression | journal = Neuroscience Research | volume = 53 | issue = 1 | pages = 69–76 | date = September 2005 | pmid = 16005997 | doi = 10.1016/j.neures.2005.06.001 }}</ref><ref name="pmid12486144">{{cite journal | vauthors = Gurevich I, Englander MT, Adlersberg M, Siegal NB, Schmauss C | title = Modulation of serotonin 2C receptor editing by sustained changes in serotonergic neurotransmission | journal = The Journal of Neuroscience | volume = 22 | issue = 24 | pages = 10529–32 | date = December 2002 | pmid = 12486144 | doi =  }}</ref>
 
== See also ==
* [[5-HT receptor]]
* [[5-HT receptor]]
* [[5-HT2 receptor|5-HT<sub>2</sub> receptor]]
* [[Anxiety/Aggression-Driven Depression]]
* [[Norepinephrine-dopamine disinhibitor]]
== References ==
{{Reflist|33em}}


==References==
==External links==
{{Reflist|2}}
* {{UCSC gene info|HTR2C}}


==Further reading==
== Further reading ==
{{refbegin | 2}}
{{Refbegin|33em}}
{{PBB_Further_reading
* {{cite journal | vauthors = Niswender CM, Sanders-Bush E, Emeson RB | title = Identification and characterization of RNA editing events within the 5-HT2C receptor | journal = Annals of the New York Academy of Sciences | volume = 861 | issue = 1 | pages = 38–48 | date = December 1998 | pmid = 9928237 | doi = 10.1111/j.1749-6632.1998.tb10171.x | bibcode = 1998NYASA.861...38N }}
| citations =
* {{cite journal | vauthors = Hoyer D, Hannon JP, Martin GR | title = Molecular, pharmacological and functional diversity of 5-HT receptors | journal = Pharmacology Biochemistry and Behavior | volume = 71 | issue = 4 | pages = 533–54 | date = April 2002 | pmid = 11888546 | doi = 10.1016/S0091-3057(01)00746-8 }}
*{{cite journal | author=Niswender CM, Sanders-Bush E, Emeson RB |title=Identification and characterization of RNA editing events within the 5-HT2C receptor. |journal=Ann. N. Y. Acad. Sci. |volume=861 |issue= |pages= 38-48 |year= 1999 |pmid= 9928237 |doi= }}
* {{cite journal | vauthors = Raymond JR, Mukhin YV, Gelasco A, Turner J, Collinsworth G, Gettys TW, Grewal JS, Garnovskaya MN | title = Multiplicity of mechanisms of serotonin receptor signal transduction | journal = Pharmacology & Therapeutics | volume = 92 | issue = 2–3 | pages = 179–212 | year = 2002 | pmid = 11916537 | doi = 10.1016/S0163-7258(01)00169-3 }}
*{{cite journal | author=Hoyer D, Hannon JP, Martin GR |title=Molecular, pharmacological and functional diversity of 5-HT receptors. |journal=Pharmacol. Biochem. Behav. |volume=71 |issue= 4 |pages= 533-54 |year= 2002 |pmid= 11888546 |doi= }}
* {{cite journal | vauthors = Van Oekelen D, Luyten WH, Leysen JE | title = 5-HT2A and 5-HT2C receptors and their atypical regulation properties | journal = Life Sciences | volume = 72 | issue = 22 | pages = 2429–49 | date = April 2003 | pmid = 12650852 | doi = 10.1016/S0024-3205(03)00141-3 }}
*{{cite journal | author=Raymond JR, Mukhin YV, Gelasco A, ''et al.'' |title=Multiplicity of mechanisms of serotonin receptor signal transduction. |journal=Pharmacol. Ther. |volume=92 |issue= 2-3 |pages= 179-212 |year= 2002 |pmid= 11916537 |doi= }}
* {{cite journal | vauthors = Reynolds GP, Templeman LA, Zhang ZJ | title = The role of 5-HT2C receptor polymorphisms in the pharmacogenetics of antipsychotic drug treatment | journal = Progress in Neuro-Psychopharmacology & Biological Psychiatry | volume = 29 | issue = 6 | pages = 1021–8 | date = July 2005 | pmid = 15953671 | doi = 10.1016/j.pnpbp.2005.03.019 }}
*{{cite journal | author=Van Oekelen D, Luyten WH, Leysen JE |title=5-HT2A and 5-HT2C receptors and their atypical regulation properties. |journal=Life Sci. |volume=72 |issue= 22 |pages= 2429-49 |year= 2003 |pmid= 12650852 |doi= }}
* {{cite journal | vauthors = Millan MJ | title = Serotonin 5-HT2C receptors as a target for the treatment of depressive and anxious states: focus on novel therapeutic strategies | journal = Thérapie | volume = 60 | issue = 5 | pages = 441–60 | year = 2006 | pmid = 16433010 | doi = 10.2515/therapie:2005065 }}
*{{cite journal | author=Reynolds GP, Templeman LA, Zhang ZJ |title=The role of 5-HT2C receptor polymorphisms in the pharmacogenetics of antipsychotic drug treatment. |journal=Prog. Neuropsychopharmacol. Biol. Psychiatry |volume=29 |issue= 6 |pages= 1021-8 |year= 2005 |pmid= 15953671 |doi= 10.1016/j.pnpbp.2005.03.019 }}
* {{cite journal | vauthors = Milatovich A, Hsieh CL, Bonaminio G, Tecott L, Julius D, Francke U | title = Serotonin receptor 1c gene assigned to X chromosome in human (band q24) and mouse (bands D-F4) | journal = Human Molecular Genetics | volume = 1 | issue = 9 | pages = 681–4 | date = December 1992 | pmid = 1302605 | doi = 10.1093/hmg/1.9.681 }}
*{{cite journal | author=Millan MJ |title=Serotonin 5-HT2C receptors as a target for the treatment of depressive and anxious states: focus on novel therapeutic strategies. |journal=Therapie |volume=60 |issue= 5 |pages= 441-60 |year= 2006 |pmid= 16433010 |doi= }}
* {{cite journal | vauthors = Saltzman AG, Morse B, Whitman MM, Ivanshchenko Y, Jaye M, Felder S | title = Cloning of the human serotonin 5-HT2 and 5-HT1C receptor subtypes | journal = Biochemical and Biophysical Research Communications | volume = 181 | issue = 3 | pages = 1469–78 | date = December 1991 | pmid = 1722404 | doi = 10.1016/0006-291X(91)92105-S }}
*{{cite journal | author=Milatovich A, Hsieh CL, Bonaminio G, ''et al.'' |title=Serotonin receptor 1c gene assigned to X chromosome in human (band q24) and mouse (bands D-F4). |journal=Hum. Mol. Genet. |volume=1 |issue= 9 |pages= 681-4 |year= 1993 |pmid= 1302605 |doi= }}
* {{cite journal | vauthors = Lappalainen J, Zhang L, Dean M, Oz M, Ozaki N, Yu DH, Virkkunen M, Weight F, Linnoila M, Goldman D | title = Identification, expression, and pharmacology of a Cys23-Ser23 substitution in the human 5-HT2c receptor gene (HTR2C) | journal = Genomics | volume = 27 | issue = 2 | pages = 274–9 | date = May 1995 | pmid = 7557992 | doi = 10.1006/geno.1995.1042 }}
*{{cite journal | author=Saltzman AG, Morse B, Whitman MM, ''et al.'' |title=Cloning of the human serotonin 5-HT2 and 5-HT1C receptor subtypes. |journal=Biochem. Biophys. Res. Commun. |volume=181 |issue= 3 |pages= 1469-78 |year= 1992 |pmid= 1722404 |doi= }}
* {{cite journal | vauthors = Tecott LH, Sun LM, Akana SF, Strack AM, Lowenstein DH, Dallman MF, Julius D | title = Eating disorder and epilepsy in mice lacking 5-HT2c serotonin receptors | journal = Nature | volume = 374 | issue = 6522 | pages = 542–6 | date = April 1995 | pmid = 7700379 | doi = 10.1038/374542a0 | bibcode = 1995Natur.374..542T }}
*{{cite journal | author=Lappalainen J, Zhang L, Dean M, ''et al.'' |title=Identification, expression, and pharmacology of a Cys23-Ser23 substitution in the human 5-HT2c receptor gene (HTR2C). |journal=Genomics |volume=27 |issue= 2 |pages= 274-9 |year= 1995 |pmid= 7557992 |doi= 10.1006/geno.1995.1042 }}
* {{cite journal | vauthors = Stam NJ, Vanderheyden P, van Alebeek C, Klomp J, de Boer T, van Delft AM, Olijve W | title = Genomic organisation and functional expression of the gene encoding the human serotonin 5-HT2C receptor | journal = European Journal of Pharmacology | volume = 269 | issue = 3 | pages = 339–48 | date = November 1994 | pmid = 7895773 | doi = 10.1016/0922-4106(94)90042-6 }}
*{{cite journal | author=Tecott LH, Sun LM, Akana SF, ''et al.'' |title=Eating disorder and epilepsy in mice lacking 5-HT2c serotonin receptors. |journal=Nature |volume=374 |issue= 6522 |pages= 542-6 |year= 1995 |pmid= 7700379 |doi= 10.1038/374542a0 }}
* {{cite journal | vauthors = Xie E, Zhu L, Zhao L, Chang LS | title = The human serotonin 5-HT2C receptor: complete cDNA, genomic structure, and alternatively spliced variant | journal = Genomics | volume = 35 | issue = 3 | pages = 551–61 | date = August 1996 | pmid = 8812491 | doi = 10.1006/geno.1996.0397 }}
*{{cite journal | author=Stam NJ, Vanderheyden P, van Alebeek C, ''et al.'' |title=Genomic organisation and functional expression of the gene encoding the human serotonin 5-HT2C receptor. |journal=Eur. J. Pharmacol. |volume=269 |issue= 3 |pages= 339-48 |year= 1995 |pmid= 7895773 |doi= }}
* {{cite journal | vauthors = Burns CM, Chu H, Rueter SM, Hutchinson LK, Canton H, Sanders-Bush E, Emeson RB | title = Regulation of serotonin-2C receptor G-protein coupling by RNA editing | journal = Nature | volume = 387 | issue = 6630 | pages = 303–8 | date = May 1997 | pmid = 9153397 | doi = 10.1038/387303a0 | bibcode = 1997Natur.387..303B }}
*{{cite journal | author=Xie E, Zhu L, Zhao L, Chang LS |title=The human serotonin 5-HT2C receptor: complete cDNA, genomic structure, and alternatively spliced variant. |journal=Genomics |volume=35 |issue= 3 |pages= 551-61 |year= 1996 |pmid= 8812491 |doi= 10.1006/geno.1996.0397 }}
* {{cite journal | vauthors = Brennan TJ, Seeley WW, Kilgard M, Schreiner CE, Tecott LH | title = Sound-induced seizures in serotonin 5-HT2c receptor mutant mice | journal = Nature Genetics | volume = 16 | issue = 4 | pages = 387–90 | date = August 1997 | pmid = 9241279 | doi = 10.1038/ng0897-387 }}
*{{cite journal | author=Burns CM, Chu H, Rueter SM, ''et al.'' |title=Regulation of serotonin-2C receptor G-protein coupling by RNA editing. |journal=Nature |volume=387 |issue= 6630 |pages= 303-8 |year= 1997 |pmid= 9153397 |doi= 10.1038/387303a0 }}
* {{cite journal | vauthors = Ullmer C, Schmuck K, Figge A, Lübbert H | title = Cloning and characterization of MUPP1, a novel PDZ domain protein | journal = FEBS Letters | volume = 424 | issue = 1–2 | pages = 63–8 | date = March 1998 | pmid = 9537516 | doi = 10.1016/S0014-5793(98)00141-0 }}
*{{cite journal | author=Brennan TJ, Seeley WW, Kilgard M, ''et al.'' |title=Sound-induced seizures in serotonin 5-HT2c receptor mutant mice. |journal=Nat. Genet. |volume=16 |issue= 4 |pages= 387-90 |year= 1997 |pmid= 9241279 |doi= 10.1038/ng0897-387 }}
* {{cite journal | vauthors = Samochowiec J, Smolka M, Winterer G, Rommelspacher H, Schmidt LG, Sander T | title = Association analysis between a Cys23Ser substitution polymorphism of the human 5-HT2c receptor gene and neuronal hyperexcitability | journal = American Journal of Medical Genetics | volume = 88 | issue = 2 | pages = 126–30 | date = April 1999 | pmid = 10206230 | doi = 10.1002/(SICI)1096-8628(19990416)88:2<126::AID-AJMG6>3.0.CO;2-M }}
*{{cite journal | author=Ullmer C, Schmuck K, Figge A, Lübbert H |title=Cloning and characterization of MUPP1, a novel PDZ domain protein. |journal=FEBS Lett. |volume=424 |issue= 1-2 |pages= 63-8 |year= 1998 |pmid= 9537516 |doi= }}
* {{cite journal | vauthors = Cargill M, Altshuler D, Ireland J, Sklar P, Ardlie K, Patil N, Shaw N, Lane CR, Lim EP, Kalyanaraman N, Nemesh J, Ziaugra L, Friedland L, Rolfe A, Warrington J, Lipshutz R, Daley GQ, Lander ES | title = Characterization of single-nucleotide polymorphisms in coding regions of human genes | journal = Nature Genetics | volume = 22 | issue = 3 | pages = 231–8 | date = July 1999 | pmid = 10391209 | doi = 10.1038/10290 }}
*{{cite journal | author=Samochowiec J, Smolka M, Winterer G, ''et al.'' |title=Association analysis between a Cys23Ser substitution polymorphism of the human 5-HT2c receptor gene and neuronal hyperexcitability. |journal=Am. J. Med. Genet. |volume=88 |issue= 2 |pages= 126-30 |year= 1999 |pmid= 10206230 |doi= }}
* {{cite journal | vauthors = Marshall SE, Bird TG, Hart K, Welsh KI | title = Unified approach to the analysis of genetic variation in serotonergic pathways | journal = American Journal of Medical Genetics | volume = 88 | issue = 6 | pages = 621–7 | date = December 1999 | pmid = 10581480 | doi = 10.1002/(SICI)1096-8628(19991215)88:6<621::AID-AJMG9>3.0.CO;2-H }}
*{{cite journal  | author=Cargill M, Altshuler D, Ireland J, ''et al.'' |title=Characterization of single-nucleotide polymorphisms in coding regions of human genes. |journal=Nat. Genet. |volume=22 |issue= 3 |pages= 231-8 |year= 1999 |pmid= 10391209 |doi= 10.1038/10290 }}
* {{cite journal | vauthors = Backstrom JR, Price RD, Reasoner DT, Sanders-Bush E | title = Deletion of the serotonin 5-HT2C receptor PDZ recognition motif prevents receptor phosphorylation and delays resensitization of receptor responses | journal = The Journal of Biological Chemistry | volume = 275 | issue = 31 | pages = 23620–6 | date = August 2000 | pmid = 10816555 | doi = 10.1074/jbc.M000922200 }}
*{{cite journal | author=Marshall SE, Bird TG, Hart K, Welsh KI |title=Unified approach to the analysis of genetic variation in serotonergic pathways. |journal=Am. J. Med. Genet. |volume=88 |issue= 6 |pages= 621-7 |year= 2000 |pmid= 10581480 |doi= }}
{{Refend}}
*{{cite journal | author=Backstrom JR, Price RD, Reasoner DT, Sanders-Bush E |title=Deletion of the serotonin 5-HT2C receptor PDZ recognition motif prevents receptor phosphorylation and delays resensitization of receptor responses. |journal=J. Biol. Chem. |volume=275 |issue= 31 |pages= 23620-6 |year= 2000 |pmid= 10816555 |doi= 10.1074/jbc.M000922200 }}
}}
{{refend}}


{{NLM content}}
{{NLM content}}
{{membrane-protein-stub}}


{{G protein-coupled receptors}}
{{G protein-coupled receptors}}
{{Cell signaling}}
{{Cell signaling}}
{{Serotonergics}}
{{Obsessive–compulsive disorder}}


[[Category:G protein coupled receptors]]
{{DEFAULTSORT:5-Ht2c Receptor}}
[[Category:Serotonin receptors]]

Latest revision as of 16:24, 8 November 2018

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The 5-HT2C receptor is a subtype of 5-HT receptor that binds the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). It is a G protein-coupled receptor (GPCR) that is coupled to Gq/G11 and mediates excitatory neurotransmission. HTR2C denotes the human gene encoding for the receptor,[1][2] that in humans is located at the X chromosome. As males have one copy of the gene and in females one of the two copies of the gene is repressed, polymorphisms at this receptor can affect the two sexes to differing extent.

Structure

At the cell surface the receptor exists as a homodimer.[3] The crystal structure is known since 2018.[4]

Distribution

5-HT2C receptors are located mainly in the choroid plexus,[5] and in rats is also found in many other brain regions in high concentrations, including parts of the hippocampus, anterior olfactory nucleus, substantia nigra, several brainstem nuclei, amygdala, subthalamic nucleus and lateral habenula. 5-HT2C receptors are also found on epithelial cells lining the ventricles.[6]

Function

The 5-HT2C receptor is one of the many binding sites for serotonin. Activation of this receptor by serotonin inhibits dopamine and norepinephrine release in certain areas of the brain.[7]

5-HT2C receptors are claimed to significantly regulate mood, anxiety, feeding, and reproductive behavior.[8] 5-HT2C receptors regulate dopamine release in the striatum, prefrontal cortex, nucleus accumbens, hippocampus, hypothalamus, and amygdala, among others.

Research indicates that some suicide victims have an abnormally high number of 5-HT2C receptors in the prefrontal cortex.[9] There is some mixed evidence that agomelatine, a 5-HT2C antagonist, is an effective antidepressant.[10] Antagonism of 5-HT2C receptors by agomelatine results in an increase of dopamine and norepinephrine activity in the frontal cortex. Conversely, many SSRIs (but not fluoxetine, which is a 5-HT2C antagonist[11]) indirectly stimulate 5-HT2C activity by increasing levels of serotonin in the synapse although the delayed mood elevation that is usually typical of SSRIs is usually paralleled by the downregulation of the 5-HT2C receptors.[12] Many atypical antipsychotics block 5-HT2C receptors, but their clinical use is limited by multiple undesirable actions on various neurotransmitters and receptors. Fluoxetine acts as a direct 5-HT2C antagonist in addition to inhibiting serotonin reuptake, however, the clinical significance of this action is variable.[11]

An overactivity of 5-HT2C receptors may contribute to depressive and anxiety symptoms in a certain population of patients. Activation of 5-HT2C by serotonin is responsible for many of the negative side effects of SSRI and SNRI medications, such as sertraline, paroxetine, venlafaxine, and others. Some of the initial anxiety caused by SSRIs is due to excessive signalling at 5-HT2C. Over a period of 1–2 weeks, the receptor begins to downregulate, along with the downregulation of 5-HT2A, 5-HT1A, and other serotonin receptors. This downregulation parallels the onset of the clinical benefits of SSRIs. 5-HT2C receptors exhibit constitutive activity in vivo, and may retain the ability to influence neurotransmission in the absence of ligand occupancy. Thus, 5-HT2C receptors do not require binding by a ligand (serotonin) in order to exhibit influence on neurotransmission. Inverse agonists may be required to fully extinguish 5-HT2C constitutive activity, and may prove useful in the treatment of 5-HT2C-mediated conditions in the absence of typical serotonin activity.[12] In addition to the evidence for a role of 5-HT2C receptor stimulation in depressive symptoms there also is evidence that activation of 5-HT2C receptors may have beneficial effects upon certain aspects of depression, one group of researchers found that direct stimulation of 5-HT2C receptors with a 5-HT2C agonist reduced cognitive deficits in mice with a TPH2 loss-of-function mutation.[13]

5-HT2C receptors mediate the release and increase of extracellular dopamine in response to many drugs,[14][15] including caffeine, nicotine, amphetamine, morphine, cocaine, and others. 5-HT2C antagonism increases dopamine release in response to reinforcing drugs, and many dopaminergic stimuli. Feeding, social interaction, and sexual activity all release dopamine subject to inhibition of 5-HT2C. Increased 5-HT2C expression reduces dopamine release in both the presence and absence of stimuli.

Conditions that increase cytokine levels in the human body may have potential to raise 5-HT2C gene expression in the brain. This could possibly comprise a link between viral infections and associated depression. Cytokine therapy has been shown to increase 5-HT2C gene expression, resulting in increased activity of 5-HT2C receptors in the brain[citation needed].

Endocrinology

Serotonin is involved in basal and stress-induced regulation of hypothalamus and pituitary gland hormones such as prolactin, adrenocorticotropic hormone (ACTH), vasopressin and oxytocin, mainly via actions of receptor subtypes 5-HT2A and 5-HT2C.[16] Therefore, the 5-HT2C receptor is a significant modulator of the hypothalamic–pituitary–adrenal axis (HPA axis).[17] The HPA axis is the main controller of acute sympathetic stress responses related to fight-or-flight response. Prolonged activation and disturbances of the HPA axis contribute to depressive and anxiety symptoms seen in many psychopathological conditions.

Stimulation of 5-HT2C receptors leads to increase of corticotropin releasing hormone (CRH) and vasopressin mRNA in the paraventricular nucleus and proopiomelanocortin in the anterior pituitary lobe. In rats, restraint stress (which can produce depressive symptoms if being chronic) induces secretion of prolactin, ACTH, vasopressin and oxytocin which is partially mediated via 5-HT2C receptor. Responses during such conditions as dehydration or haemorrhage causes the release oxytocin via serotonergic response that is partly mediated via 5-HT2C. In addition, peripheral release of vasopressin involves serotonergic response which is partially mediated via 5-HT2C.

Expression of the 5-HT2C receptor in the CNS is modulated by female sex hormones estradiol and progesterone. Combination of the hormones decrease the receptor concentration in the ventral hippocampus in rats and could thus affect mood.[18]

Genetics

Many human polymorphisms have been identified influencing the expression of 5-HT2C. Significant correlations are suggested, specifically in relation to psychiatric disorders such as depression, OCD, and anxiety-related conditions. Polymorphisms also correlate with susceptibility to a number of conditions including drug abuse and obesity. There are indications that the alternative splicing of the 5-HT2C receptor is regulated by a snoRNA called SNORD115, the deletion of which is associated with Prader–Willi syndrome.[19][20] As the human gene is located in the X chromosome, males have only one copy of the gene whereas women have two, meaning that mutations in the gene affect the phenotype of men even when the allele would be recessive in nature. As women have two copies of the gene, but only one allele is expressed in each cell, they are a mosaic for polymorphisms, meaning that one genetic variant may be prevalent in one tissue and another variant will be prevalent in a different tissue (as with all other x-linked genetic variations).

Ligands

First allosteric modulators were developed in 2018.[21]

Agonists

Partial agonists

Antagonists

Inverse agonists

Interactions

The 5-HT2C receptor has been shown to interact with MPDZ.[25][26]

RNA editing

5HT2CR pre-mRNA can be the subject of RNA editing.[27] It is the only serotonin receptor as well as the only member of the large family of 7 transmembrane receptors (7TMRs) known to be edited. Different levels of editing result in a variety of effects on receptor function.

Type

The type of RNA editing that occurs in the pre-mRNA of the 5HT2CR is Adenosine to Inosine (A to I) editing.

A to I RNA editing is catalyzed by a family of adenosine deaminases acting on RNA (ADARs) that specifically recognize adenosines within double-stranded regions of pre-mRNAs and deaminate them to inosine. Inosines are recognised as guanosine by the cells translational machinery. There are three members of the ADAR family ADARs 1-3 with ADAR1 and ADAR2 being the only enzymatically active members. ADAR3 is thought to have a regulatory role in the brain. ADAR1 and ADAR2 are widely expressed in tissues while ADAR3 is restricted to the brain. The double stranded regions of RNA are formed by base-pairing between residues in the close to region of the editing site with residues usually in a neighboring intron but can be an exonic sequence. The region that base pairs with the editing region is known as an Editing Complementary Sequence (ECS).

ADARs bind interact directly with the dsRNA substrate via their double stranded RNA binding domains. If an editing site occurs within a coding sequence, it can result in a codon change. This can lead to translation of a protein isoform due to a change in its primary protein structure. Therefore, editing can also alter protein function. A to I editing occurs in a non coding RNA sequences such as introns, untranslated regions (UTRs), LINEs, SINEs ( especially Alu repeats) The function of A to I editing in these regions is thought to involve creation of splice sites and retention of RNAs in the nucleus amongst others.

Location

Editing occurs in 5 different closely located sites within exon 5, which corresponds to the second intracellular loop of the final protein. The sites are known as A, B, C′ (previously called E), C and D, and are predicted to occur within amino acid positions 156, 158 and 160. Several codon changes can occur due to A-to-I editing at these sites. Thirty-two different mRNA variants can occur leading to 24 different protein isoforms.

  1. An Isoleucine to Valine (I/V) at amino acid position 157,161.
  2. An Isoleucine to a Methionine(I/M) at amino acid position 157
  3. An Aspartate to a Serine (N/S)at 159
  4. An Aspartate to Asparagine(N/D) at 159
  5. An Asparagine to a Glycine(N/G) at 159.

These codon changes which can occur due to A to I editing at these sites can lead to a maximum of 32 different mRNA variants leading to 24 different protein isoforms. The number of protein isoforms is less than 32 since some amino acids are encoded by more than one codon.[28] Another editing site, site F has also been located in the exon complementary sequence (ECS) of intron 5.[29] The ECS required for formation of double stranded RNA structure is found within intron 5.[27]

Conservation

RNA editing of this receptor occurs at 4 locations in the rat.[27] Editing also occurs in the mouse.[30] The initial demonstration of RNA editing in rat.[27] The predominant isoform in rat brain is VNV which differs from the most common type found in humans.[27][31] The editing complementary sequence is known to be conserved across Mammalia.

Regulation

The 5-HT2c receptor is the only serotonin receptor edited despite its close sequence similarities to other family members.[31] 5HT2CR is different due to possessing an imperfect inverted repeat at the end of exon 5 and the beginning of intron 5 allowing formation of an RNA duplex producing the dsRNA required by ADARs for editing. Disruption of this inverted repeat was demonstrated to cease all editing.[27] The different 5HT2CR mRNA isoforms are expressed differently throughout the brain, yet not all of the 24 have been detected perhaps due to tissue specific expression or low frequency editing of a particular type. Those isoforms that are not expressed at all or at a very low frequency are linked by being edited only at site C' and/or site B but not at site A. Some examples of differences in frequency of editing and site edited in different parts of the human brain of 5HT2CR include low frequency of editing in cerebellum and nearly all editing is at site D while in the hippocampus editing frequency is higher with site A being the main editing site. Site C' is only found edited in the thalamus. The most common isoform in human brain is the VSV isoform.[28][31][32]

Mice knock out and other studies have been used to determine which ADAR enzyme are involved in editing. Editing at A and B sites has been demonstrated to be due to ADAR1 editing.[33][34][35] Also since ADAR1 expression is increased in response to the presence of interferon α, it was also observed that editing at A and B sites was also increased because of this.[33] C' and D sites require ADAR2 and editing is decreased by the presence of ADAR1 with editing of C' site only observed in ADAR1 double knock out mice.[36] The C site has been shown to be mainly edited by ADAR2 but in presence of upregulated expression of ADAR1, there was an increase in editing of this site and the enzymes presence can also result in limited editing in ADAR 2 knock out mice.[33][36] This demonstrates that there must be some form interaction between the two A to I editing enzymes. Also such interactions and tissue specific expression of ADARs interaction may explain the variety in editing patterns in different regions of the brain.

Consequences

Second, the editing pattern controls the amount of the 5-HT2CR mRNA that leads to the expression of full-length protein through the modulation of alternative splice site selection 76,77. Among three alternative splice donor sites (GU1 to GU3; Fig. 4C), GU2 is the only site that forms the mature mRNA to produce the functional, full-length 5-HT2CR protein. Unedited pre-mRNAs tend to be spliced at the GU1 site, resulting in the truncated, non-functional protein if translated 76,77. However, most pre-mRNAs edited at more than one position are spliced at GU2 77. Thus, when editing is inefficient, increased splicing at GU1 may act as a control mechanism to decrease biosynthesis of the 5-HT2CR-INI and thereby limit serotonin response. Third, RNA editing controls the ultimate physiological output of constitutively active receptors by affecting the cell surface expression of the 5-HT2CR. The 5-HT2CR-VGV, which displays the lowest level of constitutive activity, is fully expressed at the cell surface under basal conditions and is rapidly internalized in the presence of agonist 78. In contrast, the 5-HT2CR-INI is constitutively internalized and accumulates in endosomes 78.

Structure

As mentioned editing results in several codon changes.The editing sites are found in the second intracellular domain of the protein which is also the receptors G protein coupling domain.Therefore, editing of these sites can affect the affinity of the receptor for G protein binding.[27]

Function

Editing results in reduced affinity for specific G proteins which in turn affects internal signalling via second messengers (Phospholipase C signalling system). The fully edited isoform, VGV, considerably reduces 5-HT potency, G-protein coupling and agonist binding, compared to the unedited protein isoform, INI. 72-76. Most evidence for the effect of editing on function comes from downstream measurements of receptor activity, radio ligand binding and functional studies.Inhibitory effects are linked to the extent of editing.Those isoforms with a higher level of editing require higher levels of serotonin to activate the phospholipase c pathway. Unedited INI form has a greater tendency to isomerise to an active form which can more easily interact with G proteins. This indicates that RNA editing here may be a mechanism for regulating neuronal excitability by stabilising receptor signalling.[27][31]

Editing is also thought to function in cell surface expression of the receptor subtype. The fully edited VGV, which has the lowest level of constitutive activity, is fully expressed at the cell surface while the non-edited INI is internalised and accumulates in endosome.[37]

Editing is also thought to influence splicing. Three different spliced isoforms of the receptor exist. Editing regulates the amount of 5HT2CR mRNA which leads to translation of the full length protein selection of alternative splice sites. t76,77. These splice sites are termed Gu1, Gu2, GU3. Only GU2 site splicing results in translation of the full length receptor while editing at GU1 is known to result in translation of a truncated protein. This is thought to be a regulatory mechanism to decrease the amount of unedited isoform INI to limit serotonin response when editing is inefficient. Most of the pre-mRNAs which are edited are spliced at the GU2 site.[29][32]

Dysregulation

Serotonin family of receptors are often linked to pathology of several human mental conditions such as Schizophrenia, anxiety, Bipolar disorder and major depression.[38] There have been several experimental investigations into the effects of alternative editing patterns of the 5HT2CR and these conditions with a wide variability in results especially those relating to schizophrenia.[39] Some studies have noted that there is an increase in RNA editing at site A in depressed suicide victims.[9][39] E site editing was observed to be increased in individuals suffering from major depression.[40] In rat models this increase is also observed and can be reversed with fluoxetine with some suggestion that E site editing maybe linked to major depression.[41][42]

See also

References

  1. "Entrez Gene: HTR2C 5-hydroxytryptamine (serotonin) receptor 2C".
  2. Stam NJ, Vanderheyden P, van Alebeek C, Klomp J, de Boer T, van Delft AM, Olijve W (November 1994). "Genomic organisation and functional expression of the gene encoding the human serotonin 5-HT2C receptor". European Journal of Pharmacology. 269 (3): 339–48. doi:10.1016/0922-4106(94)90042-6. PMID 7895773.
  3. Herrick-Davis K, Grinde E, Lindsley T, Cowan A, Mazurkiewicz JE (July 2012). "Oligomer size of the serotonin 5-hydroxytryptamine 2C (5-HT2C) receptor revealed by fluorescence correlation spectroscopy with photon counting histogram analysis: evidence for homodimers without monomers or tetramers". The Journal of Biological Chemistry. 287 (28): 23604–14. doi:10.1074/jbc.M112.350249. PMC 3390635. PMID 22593582.
  4. Peng Y, McCorvy JD, Harpsøe K, Lansu K, Yuan S, Popov P, Qu L, Pu M, Che T, Nikolajsen LF, Huang XP, Wu Y, Shen L, Bjørn-Yoshimoto WE, Ding K, Wacker D, Han GW, Cheng J, Katritch V, Jensen AA, Hanson MA, Zhao S, Gloriam DE, Roth BL, Stevens RC, Liu ZJ (February 2018). "5-HT2C Receptor Structures Reveal the Structural Basis of GPCR Polypharmacology". Cell. 172 (4): 719–730.e14. doi:10.1016/j.cell.2018.01.001. PMID 29398112.
  5. Abramowski D, Rigo M, Duc D, Hoyer D, Staufenbiel M (1995). "Localization of the 5-Hydroxytryptamine2c Receptor Protein in Human and Rat Brain Using Specific Antisera". Neuropharmacology. 34 (12): 1635–1645. doi:10.1016/0028-3908(95)00138-7. PMID 8788961.
  6. Hoffman BJ, Mezey E (1989). "Distribution of serotonin 5-HT1C receptor mRNA in adult rat brain". FEBS Letters. 247 (2): 453–62. doi:10.1016/0014-5793(89)81390-0. PMID 2714444.
  7. Alex KD, Yavanian GJ, McFarlane HG, Pluto CP, Pehek EA (March 2005). "Modulation of dopamine release by striatal 5-HT2C receptors". Synapse. 55 (4): 242–51. doi:10.1002/syn.20109. PMID 15668911.
  8. Heisler LK, Zhou L, Bajwa P, Hsu J, Tecott LH (July 2007). "Serotonin 5-HT(2C) receptors regulate anxiety-like behavior". Genes, Brain, and Behavior. 6 (5): 491–6. doi:10.1111/j.1601-183X.2007.00316.x. PMID 17451451.
  9. 9.0 9.1 Niswender CM, Herrick-Davis K, Dilley GE, Meltzer HY, Overholser JC, Stockmeier CA, Emeson RB, Sanders-Bush E (May 2001). "RNA editing of the human serotonin 5-HT2C receptor. alterations in suicide and implications for serotonergic pharmacotherapy". Neuropsychopharmacology. 24 (5): 478–91. doi:10.1016/S0893-133X(00)00223-2. PMID 11282248.
  10. Eser D, Baghai TC, Möller HJ (2010). "Agomelatine: The evidence for its place in the treatment of depression". Core Evidence. 4: 171–9. doi:10.2147/CE.S6005. PMC 2899775. PMID 20694073.
  11. 11.0 11.1 Ni YG, Miledi R (March 1997). "Blockage of 5HT2C serotonin receptors by fluoxetine (Prozac)". Proceedings of the National Academy of Sciences of the United States of America. 94 (5): 2036–40. Bibcode:1997PNAS...94.2036N. doi:10.1073/pnas.94.5.2036. PMC 20038. PMID 9050900.
  12. 12.0 12.1 Berg KA, Harvey JA, Spampinato U, Clarke WP (December 2005). "Physiological relevance of constitutive activity of 5-HT2A and 5-HT2C receptors". Trends in Pharmacological Sciences. 26 (12): 625–30. doi:10.1016/j.tips.2005.10.008. PMID 16269190.
  13. Del'Guidice T, Lemay F, Lemasson M, Levasseur-Moreau J, Manta S, Etievant A, Escoffier G, Doré FY, Roman FS, Beaulieu JM (April 2014). "Stimulation of 5-HT2C receptors improves cognitive deficits induced by human tryptophan hydroxylase 2 loss of function mutation". Neuropsychopharmacology. 39 (5): 1125–34. doi:10.1038/npp.2013.313. PMC 3957106. PMID 24196946.
  14. Esposito E (February 2006). "Serotonin-dopamine interaction as a focus of novel antidepressant drugs". Current Drug Targets. 7 (2): 177–85. doi:10.2174/138945006775515455. PMID 16475959.
  15. Bubar MJ, Cunningham KA (2006). "Serotonin 5-HT2A and 5-HT2C receptors as potential targets for modulation of psychostimulant use and dependence". Current Topics in Medicinal Chemistry. 6 (18): 1971–85. doi:10.2174/156802606778522131. PMID 17017968.
  16. Jørgensen HS (November 2007). "Studies on the neuroendocrine role of serotonin". Danish Medical Bulletin. 54 (4): 266–88. PMID 18208678.
  17. Heisler LK, Pronchuk N, Nonogaki K, Zhou L, Raber J, Tung L, Yeo GS, O'Rahilly S, Colmers WF, Elmquist JK, Tecott LH (June 2007). "Serotonin activates the hypothalamic-pituitary-adrenal axis via serotonin 2C receptor stimulation". The Journal of Neuroscience. 27 (26): 6956–64. doi:10.1523/JNEUROSCI.2584-06.2007. PMID 17596444.
  18. Birzniece V, Johansson IM, Wang MD, Bäckström T, Olsson T (February 2002). "Ovarian hormone effects on 5-hydroxytryptamine(2A) and 5-hydroxytryptamine(2C) receptor mRNA expression in the ventral hippocampus and frontal cortex of female rats". Neuroscience Letters. 319 (3): 157–61. doi:10.1016/S0304-3940(01)02570-8. PMID 11834317.
  19. Kishore S, Stamm S (January 2006). "The snoRNA HBII-52 regulates alternative splicing of the serotonin receptor 2C". Science. 311 (5758): 230–2. Bibcode:2006Sci...311..230K. doi:10.1126/science.1118265. PMID 16357227.
  20. Sahoo T, del Gaudio D, German JR, Shinawi M, Peters SU, Person RE, Garnica A, Cheung SW, Beaudet AL (June 2008). "Prader-Willi phenotype caused by paternal deficiency for the HBII-85 C/D box small nucleolar RNA cluster". Nature Genetics. 40 (6): 719–21. doi:10.1038/ng.158. PMC 2705197. PMID 18500341.
  21. Wild CT, Miszkiel JM, Wold EA, Soto CA, Ding C, Hartley RM, White MA, Anastasio NC, Cunningham KA, Zhou J (April 2018). "Design, Synthesis, and Characterization of 4-Undecylpiperidine-2-carboxamides as Positive Allosteric Modulators of the Serotonin (5-HT) 5-HT2C Receptor". J. Med. Chem. doi:10.1021/acs.jmedchem.8b00401. PMID 29620897.
  22. Rodriguez MM, Overshiner C, Leander JD, Li X, Morrow D, Conway RG, Nelson DL, Briner K, Witkin JM (2017). "Behavioral Effects of a Novel Benzofuranyl-Piperazine Serotonin-2C Receptor Agonist Suggest a Potential Therapeutic Application in the Treatment of Obsessive-Compulsive Disorder". Front Psychiatry. 8: 89. doi:10.3389/fpsyt.2017.00089. PMC 5438973. PMID 28588509.
  23. McCorvy JD, Harland AA, Maglathlin R, Nichols DE. A 5-HT(2C) receptor antagonist potentiates a low dose amphetamine-induced conditioned place preference. Neuroscience Letters. 2011 November 7;505(1):10-3. PMID 21827831
  24. Dekeyne A, Brocco M, Loiseau F, Gobert A, Rivet JM, Di Cara B, Cremers TI, Flik G, Fone KC, Watson DJ, Papp M, Sharp T, Serres F, Cespuglio R, Olivier B, Chan JS, Lavielle G, Millan MJ (March 2012). "S32212, a novel serotonin type 2C receptor inverse agonist/α2-adrenoceptor antagonist and potential antidepressant: II. A behavioral, neurochemical, and electrophysiological characterization". The Journal of Pharmacology and Experimental Therapeutics. 340 (3): 765–80. doi:10.1124/jpet.111.187534. PMID 22178753.
  25. Becamel C, Figge A, Poliak S, Dumuis A, Peles E, Bockaert J, Lubbert H, Ullmer C (April 2001). "Interaction of serotonin 5-hydroxytryptamine type 2C receptors with PDZ10 of the multi-PDZ domain protein MUPP1". The Journal of Biological Chemistry. 276 (16): 12974–82. doi:10.1074/jbc.M008089200. PMID 11150294.
  26. Ullmer C, Schmuck K, Figge A, Lübbert H (March 1998). "Cloning and characterization of MUPP1, a novel PDZ domain protein". FEBS Letters. 424 (1–2): 63–8. doi:10.1016/S0014-5793(98)00141-0. PMID 9537516.
  27. 27.0 27.1 27.2 27.3 27.4 27.5 27.6 27.7 Burns CM, Chu H, Rueter SM, Hutchinson LK, Canton H, Sanders-Bush E, Emeson RB (May 1997). "Regulation of serotonin-2C receptor G-protein coupling by RNA editing". Nature. 387 (6630): 303–8. Bibcode:1997Natur.387..303B. doi:10.1038/387303a0. PMID 9153397.
  28. 28.0 28.1 Fitzgerald LW, Iyer G, Conklin DS, Krause CM, Marshall A, Patterson JP, Tran DP, Jonak GJ, Hartig PR (August 1999). "Messenger RNA editing of the human serotonin 5-HT2C receptor". Neuropsychopharmacology. 21 (2 Suppl): 82S–90S. doi:10.1016/S0893-133X(99)00004-4. PMID 10432493.
  29. 29.0 29.1 Flomen R, Knight J, Sham P, Kerwin R, Makoff A (2004). "Evidence that RNA editing modulates splice site selection in the 5-HT2C receptor gene". Nucleic Acids Research. 32 (7): 2113–22. doi:10.1093/nar/gkh536. PMC 407821. PMID 15087490.
  30. Hackler EA, Airey DC, Shannon CC, Sodhi MS, Sanders-Bush E (May 2006). "5-HT(2C) receptor RNA editing in the amygdala of C57BL/6J, DBA/2J, and BALB/cJ mice". Neuroscience Research. 55 (1): 96–104. doi:10.1016/j.neures.2006.02.005. PMID 16580757.
  31. 31.0 31.1 31.2 31.3 Niswender CM, Copeland SC, Herrick-Davis K, Emeson RB, Sanders-Bush E (April 1999). "RNA editing of the human serotonin 5-hydroxytryptamine 2C receptor silences constitutive activity". The Journal of Biological Chemistry. 274 (14): 9472–8. doi:10.1074/jbc.274.14.9472. PMID 10092629.
  32. 32.0 32.1 Wang Q, O'Brien PJ, Chen CX, Cho DS, Murray JM, Nishikura K (March 2000). "Altered G protein-coupling functions of RNA editing isoform and splicing variant serotonin2C receptors". Journal of Neurochemistry. 74 (3): 1290–300. doi:10.1046/j.1471-4159.2000.741290.x. PMID 10693963.
  33. 33.0 33.1 33.2 Yang W, Wang Q, Kanes SJ, Murray JM, Nishikura K (April 2004). "Altered RNA editing of serotonin 5-HT2C receptor induced by interferon: implications for depression associated with cytokine therapy". Brain Research. Molecular Brain Research. 124 (1): 70–8. doi:10.1016/j.molbrainres.2004.02.010. PMID 15093687.
  34. Sukma M, Tohda M, Watanabe H, Matsumoto K (August 2005). "The mRNA expression differences of RNA editing enzymes in differentiated and undifferentiated NG108-15 cells". Journal of Pharmacological Sciences. 98 (4): 467–70. doi:10.1254/jphs.SC0050074. PMID 16082172.
  35. Tohda M, Sukma M, Watanabe H (October 2004). "RNA editing and short variant of serotonin 2C receptor mRNA in neuronally differentiated NG108-15 cells". Journal of Pharmacological Sciences. 96 (2): 164–9. doi:10.1254/jphs.FP0040227. PMID 15492466.
  36. 36.0 36.1 Hartner JC, Schmittwolf C, Kispert A, Müller AM, Higuchi M, Seeburg PH (February 2004). "Liver disintegration in the mouse embryo caused by deficiency in the RNA-editing enzyme ADAR1". The Journal of Biological Chemistry. 279 (6): 4894–902. doi:10.1074/jbc.M311347200. PMID 14615479.
  37. Marion S, Weiner DM, Caron MG (January 2004). "RNA editing induces variation in desensitization and trafficking of 5-hydroxytryptamine 2c receptor isoforms". The Journal of Biological Chemistry. 279 (4): 2945–54. doi:10.1074/jbc.M308742200. PMID 14602721.
  38. Baxter G, Kennett G, Blaney F, Blackburn T (March 1995). "5-HT2 receptor subtypes: a family re-united?". Trends in Pharmacological Sciences. 16 (3): 105–10. doi:10.1016/S0165-6147(00)88991-9. PMID 7792930.
  39. 39.0 39.1 Iwamoto K, Kato T (August 2003). "RNA editing of serotonin 2C receptor in human postmortem brains of major mental disorders". Neuroscience Letters. 346 (3): 169–72. doi:10.1016/S0304-3940(03)00608-6. PMID 12853111.
  40. Gurevich I, Tamir H, Arango V, Dwork AJ, Mann JJ, Schmauss C (April 2002). "Altered editing of serotonin 2C receptor pre-mRNA in the prefrontal cortex of depressed suicide victims". Neuron. 34 (3): 349–56. doi:10.1016/S0896-6273(02)00660-8. PMID 11988167.
  41. Iwamoto K, Nakatani N, Bundo M, Yoshikawa T, Kato T (September 2005). "Altered RNA editing of serotonin 2C receptor in a rat model of depression". Neuroscience Research. 53 (1): 69–76. doi:10.1016/j.neures.2005.06.001. PMID 16005997.
  42. Gurevich I, Englander MT, Adlersberg M, Siegal NB, Schmauss C (December 2002). "Modulation of serotonin 2C receptor editing by sustained changes in serotonergic neurotransmission". The Journal of Neuroscience. 22 (24): 10529–32. PMID 12486144.

External links

Further reading

  • Niswender CM, Sanders-Bush E, Emeson RB (December 1998). "Identification and characterization of RNA editing events within the 5-HT2C receptor". Annals of the New York Academy of Sciences. 861 (1): 38–48. Bibcode:1998NYASA.861...38N. doi:10.1111/j.1749-6632.1998.tb10171.x. PMID 9928237.
  • Hoyer D, Hannon JP, Martin GR (April 2002). "Molecular, pharmacological and functional diversity of 5-HT receptors". Pharmacology Biochemistry and Behavior. 71 (4): 533–54. doi:10.1016/S0091-3057(01)00746-8. PMID 11888546.
  • Raymond JR, Mukhin YV, Gelasco A, Turner J, Collinsworth G, Gettys TW, Grewal JS, Garnovskaya MN (2002). "Multiplicity of mechanisms of serotonin receptor signal transduction". Pharmacology & Therapeutics. 92 (2–3): 179–212. doi:10.1016/S0163-7258(01)00169-3. PMID 11916537.
  • Van Oekelen D, Luyten WH, Leysen JE (April 2003). "5-HT2A and 5-HT2C receptors and their atypical regulation properties". Life Sciences. 72 (22): 2429–49. doi:10.1016/S0024-3205(03)00141-3. PMID 12650852.
  • Reynolds GP, Templeman LA, Zhang ZJ (July 2005). "The role of 5-HT2C receptor polymorphisms in the pharmacogenetics of antipsychotic drug treatment". Progress in Neuro-Psychopharmacology & Biological Psychiatry. 29 (6): 1021–8. doi:10.1016/j.pnpbp.2005.03.019. PMID 15953671.
  • Millan MJ (2006). "Serotonin 5-HT2C receptors as a target for the treatment of depressive and anxious states: focus on novel therapeutic strategies". Thérapie. 60 (5): 441–60. doi:10.2515/therapie:2005065. PMID 16433010.
  • Milatovich A, Hsieh CL, Bonaminio G, Tecott L, Julius D, Francke U (December 1992). "Serotonin receptor 1c gene assigned to X chromosome in human (band q24) and mouse (bands D-F4)". Human Molecular Genetics. 1 (9): 681–4. doi:10.1093/hmg/1.9.681. PMID 1302605.
  • Saltzman AG, Morse B, Whitman MM, Ivanshchenko Y, Jaye M, Felder S (December 1991). "Cloning of the human serotonin 5-HT2 and 5-HT1C receptor subtypes". Biochemical and Biophysical Research Communications. 181 (3): 1469–78. doi:10.1016/0006-291X(91)92105-S. PMID 1722404.
  • Lappalainen J, Zhang L, Dean M, Oz M, Ozaki N, Yu DH, Virkkunen M, Weight F, Linnoila M, Goldman D (May 1995). "Identification, expression, and pharmacology of a Cys23-Ser23 substitution in the human 5-HT2c receptor gene (HTR2C)". Genomics. 27 (2): 274–9. doi:10.1006/geno.1995.1042. PMID 7557992.
  • Tecott LH, Sun LM, Akana SF, Strack AM, Lowenstein DH, Dallman MF, Julius D (April 1995). "Eating disorder and epilepsy in mice lacking 5-HT2c serotonin receptors". Nature. 374 (6522): 542–6. Bibcode:1995Natur.374..542T. doi:10.1038/374542a0. PMID 7700379.
  • Stam NJ, Vanderheyden P, van Alebeek C, Klomp J, de Boer T, van Delft AM, Olijve W (November 1994). "Genomic organisation and functional expression of the gene encoding the human serotonin 5-HT2C receptor". European Journal of Pharmacology. 269 (3): 339–48. doi:10.1016/0922-4106(94)90042-6. PMID 7895773.
  • Xie E, Zhu L, Zhao L, Chang LS (August 1996). "The human serotonin 5-HT2C receptor: complete cDNA, genomic structure, and alternatively spliced variant". Genomics. 35 (3): 551–61. doi:10.1006/geno.1996.0397. PMID 8812491.
  • Burns CM, Chu H, Rueter SM, Hutchinson LK, Canton H, Sanders-Bush E, Emeson RB (May 1997). "Regulation of serotonin-2C receptor G-protein coupling by RNA editing". Nature. 387 (6630): 303–8. Bibcode:1997Natur.387..303B. doi:10.1038/387303a0. PMID 9153397.
  • Brennan TJ, Seeley WW, Kilgard M, Schreiner CE, Tecott LH (August 1997). "Sound-induced seizures in serotonin 5-HT2c receptor mutant mice". Nature Genetics. 16 (4): 387–90. doi:10.1038/ng0897-387. PMID 9241279.
  • Ullmer C, Schmuck K, Figge A, Lübbert H (March 1998). "Cloning and characterization of MUPP1, a novel PDZ domain protein". FEBS Letters. 424 (1–2): 63–8. doi:10.1016/S0014-5793(98)00141-0. PMID 9537516.
  • Samochowiec J, Smolka M, Winterer G, Rommelspacher H, Schmidt LG, Sander T (April 1999). "Association analysis between a Cys23Ser substitution polymorphism of the human 5-HT2c receptor gene and neuronal hyperexcitability". American Journal of Medical Genetics. 88 (2): 126–30. doi:10.1002/(SICI)1096-8628(19990416)88:2<126::AID-AJMG6>3.0.CO;2-M. PMID 10206230.
  • Cargill M, Altshuler D, Ireland J, Sklar P, Ardlie K, Patil N, Shaw N, Lane CR, Lim EP, Kalyanaraman N, Nemesh J, Ziaugra L, Friedland L, Rolfe A, Warrington J, Lipshutz R, Daley GQ, Lander ES (July 1999). "Characterization of single-nucleotide polymorphisms in coding regions of human genes". Nature Genetics. 22 (3): 231–8. doi:10.1038/10290. PMID 10391209.
  • Marshall SE, Bird TG, Hart K, Welsh KI (December 1999). "Unified approach to the analysis of genetic variation in serotonergic pathways". American Journal of Medical Genetics. 88 (6): 621–7. doi:10.1002/(SICI)1096-8628(19991215)88:6<621::AID-AJMG9>3.0.CO;2-H. PMID 10581480.
  • Backstrom JR, Price RD, Reasoner DT, Sanders-Bush E (August 2000). "Deletion of the serotonin 5-HT2C receptor PDZ recognition motif prevents receptor phosphorylation and delays resensitization of receptor responses". The Journal of Biological Chemistry. 275 (31): 23620–6. doi:10.1074/jbc.M000922200. PMID 10816555.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.